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AUTOBIOGRAPHY 


OF 


SIR  GEORGE  BIDDELL  AIRY,  K.C.B. 


I 


SonDon:  c.  J.  CLAY  AND  SONS, 

CAMBRIDGE   UNIVERSITY   PRESS  WAREHOUSE, 

AVE  MARIA   LANE. 

263,   ARGYLE  STREET. 


:    F.   A.   BROCKHAUS. 
Sorfe:    THE  MACMILLAN  CO. 


AUTOBIOGRAPHY 


OF 


SIR  GEORGE  BIDDELL  AIRY,  K.C.B., 

M.A.,   LL.D.,   D.C.L.,   F.R.S,   F.R.A.S., 

HONORARY   FELLOW  OF  TRINITY  COLLEGE,  CAMBRIDGE, 
ASTRONOMER   ROYAL  FROM    1836  TO    l88l. 


EDITED   BY 


WILFRID    AIRY,    B.A.,    M.lNST.CE, 


CAMBRIDGE: 

AT   THE   UNIVERSITY   PRESS. 
1896 

[All  Rights  reserved] 


Cambridge : 

PRINTED   BY  J.    AND  C.    F.    CLAY, 
AT  THE   UNIVERSITY  PRESS. 


PREFACE. 


THE  life  of  Airy  was  essentially  that  of  a  hard-working, 
business  man,  and  differed  from  that  of  other  hard-working 
people  only  in  the  quality  and  variety  of  his  work.  It  was 
not  an  exciting  life,  but  it  was  full  of  interest,  and  his  work 
brought  him  into  close  relations  with  many  scientific  men, 
and  with  many  men  high  in  the  State.  His  real  business 
life  commenced  after  he  became  Astronomer  Royal,  and 
from  that  time  forward,  during  the  46  years  that  he  remained 
in  office,  he  was  so  entirely  wrapped  up  in  the  duties  of  his 
post  that  the  history  of  the  Observatory  is  the  history  of  his 
life.  For  writing  his  business  life  there  is  abundant  material, 
for  he  preserved  all  his  correspondence,  and  the  chief  sources 
of  information  are  as  follows  : 

(1)  His  Autobiography. 

(2)  His  Annual  Reports  to  the  Board  of  Visitors. 

(3)  His  printed  Papers  entitled  «  Papers  by  G.  B.  Airy." 

(4)  His  miscellaneous  private  correspondence. 

(5)  His  letters  to  his  wife. 

(6)  His  business  correspondence. 

(i)  His  Autobiography,  after  the  time  that  he  became 
Astronomer  Royal,  is,  as  might  be  expected,  mainly  a  record 
of  the  scientific  work  carried  on  at  the  Greenwich  Obser- 
vatory :  but  by  no  means  exclusively  so.  About  the  time 
when  he  took  charge  of  the  Observatory  there  was  an 
immense  development  of  astronomical  enterprise :  observa- 
tories were  springing  up  in  all  directions,  and  the  Astronomer 

A  B.  239026  *. 

.*"' 


Vi  PREFACE. 


Royal  was  expected  to  advise  upon  all  of  the  British  and 
Colonial  Observatories.  It  was  'necessary  also  for  him  to 
keep  in  touch  with  the  Continental  Observatories  and  their 
work,  and  this  he  did  very  diligently  and  successfully,  both 
by  correspondence  and  personal  intercourse  with  the  foreign 
astronomers.  There  was  also  much  work  on  important 
subjects  more  or  less  connected  with  his  official  duties — such 
as  geodetical  survey  work,  the  establishment  of  time-balls 
at  different  places,  longitude  determinations,  observation  of 
eclipses,  and  the  determination  of  the  density  of  the  Earth. 
Lastly,  there  was  a  great  deal  of  time  and  work  given 
to  questions  not  very  immediately  connected  with  his  office, 
but  on  which  the  Government  asked  his  assistance  in  the 
capacity  of  general  scientific  adviser :  such  were  the  Cor- 
rection of  the  Compass  in  iron  ships,  the  Railway  Gauge 
Commission,  the  Commission  for  the  Restoration  of  the 
Standards  of  Length  and  Weight,  the  Maine  Boundary,  Light- 
houses, the  Westminster  Clock,  the  London  University,  and 
many  other  questions. 

Besides  those  above-mentioned  there  were  a  great  many 
subjects  which  he  took  up  out  of  sheer  interest  in  the 
investigations.  For  it  may  fairly  be  said  that  every  subject 
of  a  distinctly  practical  nature,  which  could  be  advanced  by 
mathematical  knowledge,  had  an  interest  for  him  :  and  his 
incessant  industry  enabled  him  to  find  time  for  many  of 
them.  Amongst  such  subjects  were  Tides  and  Tidal  Obser- 
vations, Clockwork,  and  the  Strains  in  Beams  and  Bridges. 
A  certain  portion  of  his  time  was  also  given  to  Lectures, 
generally  on  current  astronomical  questions,  for  he  held  it  as 
his  duty  to  popularize  the  science  as  far  as  lay  in  his  power. 
And  he  attended  the  meetings  of  the  Royal  Astronomical 
Society  with  great  regularity,  and  took  a  very  active  part  in 
the  discussions  and  business  of  the  Society.  He  also  did 
much  work  for  the  Royal  Society,  and  (up  to  a  certain  date) 
for  the  British  Association. 


PREFACE.  vii 


All  of  the  foregoing  matters  are  recorded  pretty  fully  in 
his  Autobiography  up  to  the  year  1861.  After  that  date  the 
Autobiography  is  given  in  a  much  more  abbreviated  form, 
and  might  rather  be  regarded  as  a  collection  of  notes  for  his 
Biography.  His  private  history  is  given  very  fully  for  the 
first  part  of  his  life,  but  is  very  lightly  touched  upon  during 
his  residence  at  Greenwich.  A  great  part  of  the  Auto- 
biography is  in  a  somewhat  disjointed  state,  and  appears  to 
have  been  formed  by  extracts  from  a  number  of  different 
sources,  such  as  Official  Journals,  Official  Correspondence, 
and  Reports.  In  editing  the  Autobiography  it  has  been 
thought  advisable  to  omit  a  large  number  of  short  notes 
relating  to  the  routine  work  of  the  Observatory,  to  technical 
and  scientific  correspondence,  to  Papers  communicated  to 
various  Societies  and  official  business  connected  with  them, 
and  to  miscellaneous  matters  of  minor  importance.  These  in 
the  aggregate  occupied  a  great  deal  of  time  and  attention. 
But,  from  their  detached  nature,  they  would  have  but  little 
general  interest.  At  various  places  will  be  found  short 
Memoirs  and  other  matter  by  the  Editor. 

(2)  All  of  his  Annual  Reports  to  the  Board  of  Visitors  are 
attached  to  his  Autobiography  and  were  evidently  intended 
to  be  read  with  it  and  to  form  part  of  it.     These  Reports 
are  so  carefully  compiled  and  are  so  copious  that  they  form 
a  very  complete  history  of  the  Greenwich  Observatory  and 
of  the  work  carried  on  there  during  the  time  that  he  was 
Astronomer  Royal.     The  first   Report  contained  only  four 
pages,  but  with  the  constantly  increasing  amount  and  range 
of  work  the  Reports  constantly  increased  in  volume  till  the 
later    Reports    contained    21    pages.      Extracts   from    these 
Reports  relating  to  matters  of  novelty  and  importance,  and 
illustrating  the  principles  which  guided  him  in  his  conduct 
of  the  Observatory,  have  been  incorporated  with  the  Auto- 
biography. 

(3)  The  printed  "  Papers  by  G.  B.  Airy  "  are  bound  in 


Vlll  PREFACE. 


14  large  quarto  volumes.  There  are  518  of  these  Papers, 
on  a  great  variety  of  subjects :  a  list  of  them  is  appended 
to  this  history,  as  also  is  a  list  of  the  books  that  he  wrote, 
and  one  or  two  of  the  Papers  which  were  separately  printed. 
They  form  a  very  important  part  of  his  life's  work,  and  are 
frequently  referred  to  in  the  present  history.  They  are 
almost  all  to  be  found  in  the  Transactions  of  Societies  or 
in  newspapers,  and  extend  over  a  period  of  63  years  (1822 
to  1885).  The  progress  made  in  certain  branches  of  science 
during  this  long  period  can  very  fairly  be  traced  by  these 
Papers. 

(4)  His  private  correspondence  was  large,  and  like  his 
other  papers  it  was  carefully  arranged.     No  business  letters 
of  any  kind  are  included    under  this  head.     In  this  corre- 
spondence letters  are  occasionally  found  either  dealing  with 
matters  of  importance  or  in  some  way  characteristic,  and 
these   have   been    inserted   in   this   biography.     As   already 
stated   the  Autobiography  left  by  Airy  is  confined  almost 
entirely  to  science  and  business,  and  touches  very  lightly  on 
private  matters  or  correspondence. 

(5)  The  letters  to  his  wife  are  very  numerous.     They 
were  written  during  his  occasional  absences  from  home  on 
business  or  for  relaxation.     On  these  occasions  he  rarely  let 
a  day  pass  without  writing  to  his  wife,  and  sometimes  he 
wrote  twice  on  the  same  day.     They  are  full  of  energy  and 
interest  and  many  extracts  from  them  are  inserted  in  this 
history.     A  great  deal  of  the  personal  history  is  taken  from 
them. 

(6)  All    correspondence    in    any   way   connected    with 
business  during  the  time  that  he   was   Astronomer    Royal 
is  to  be  found  at  the  Royal  Observatory.     It  is  all  bound 
and   arranged    in   the    most    perfect    order,   and    any   letter 
throughout  this  time  can  be  found   with  the  greatest  ease. 
It  is  very  bulky,  and  much  of  it  is,  in  a  historical  sense,  very 
interesting.    It  was  no  doubt  mainly  from  this  correspondence 


PREFACE.  IX 


that  the  Autobiography,  which  so  far  as  related  to  the 
Greenwich  part  of  it  was  almost  entirely  a  business  history, 
was  compiled. 

The  history  of  the  early  part  of  his  life  was  written  in 
great  detail  and  contained  a  large  quantity  of  family  matter 
which  was  evidently  not  intended  for  publication.  This  part 
of  the  Autobiography  has  been  compressed.  The  history  of 
the  latter  part  of  his  life  was  not  written  by  himself  at  all, 
and  has  been  compiled  from  his  Journal  and  other  sources. 
In  both  these  cases,  and  occasionally  in  short  paragraphs 
throughout  the  narrative,  it  has  been  found  convenient  to 
write  the  history  in  the  third  person. 


2,  THE  CIRCUS, 

GREENWICH. 


NOTE. 

The  Syndics  of  the  Cambridge  University  Press  desire  to  express 
their  thanks  to  Messrs  Macmillan  &  Co.  for  their  courteous  per- 
mission to  use  in  this  work  the  steel  engraving  of  Sir  George  Biddell 
Airy  published  in  Nature  on  October  31,  1878. 


' 


TABLE   OF   CONTENTS. 


CHAPTER   I. 

PAGES 

Personal  Sketch  of  George  Biddell  Airy .         .         .         .  i — 13 

CHAPTER   II. 

From  his  birth  to  his  taking  his  B.A.  Degree  at  Cam- 
bridge .  .  .  .  .  ....  14 — 48 

CHAPTER   III. 

At  Trinity  College,  Cambridge,  from  his  taking  his  B.A. 
Degree  to  his  taking  charge  of  the  Cambridge 
Observatory  as  Plumian  Professor.  .  .  .  49 — 81 

CHAPTER   IV. 

At  Cambridge  Observatory,  from  his  taking  charge  of 
the  Cambridge  Observatory  to  his  residence  at 
Greenwich  Observatory  as  Astronomer  Royal  .  82 — 122 

CHAPTER   V. 
At  Greenwich  Observatory,  1836 — 1846          .         .         .     123 — 177 

CHAPTER   VI. 

At  Greenwich  Observatory,  1846 — 1856          .      -  .         .     178 — 225 

CHAPTER   VII. 
At  Greenwich  Observatory,  1856 — 1866          .         .         ;     226 — 261 

CHAPTER   VIII. 

At  Greenwich  Observatory,  1866 — 1876          .         .         .     262 — 314 


Xll  TABLE   OF   CONTENTS. 


CHAPTER   IX. 

PAGES 

At  Greenwich  Observatory,  from  January  ist,   1876,  to 

his  resignation  of  office  on  August  i5th,  1881  .     315 — 345 

CHAPTER   X. 

At  the  White  House,  Greenwich,  from  his  resignation  of 
office  on  August  i5th,  1881,  to  his  death  on 
January  2nd,  1892  ......  346 — 368 


APPENDIX. 

List  of  Printed  Papers  by  G.  B.  Airy,  and  List  of  Books 

written  by  G.-B.  Airy      ......     369 — 404 


INDEX ...     405 — 414 


CHAPTER  I. 

PERSONAL  SKETCH  OF  GEORGE  BIDDELL  AIRY. 

THE  history  of  Airy's  life,  and  especially  the  history  of  his 
life's  work,  is  given  in  the  chapters  that  follow.  But  it  is  felt 
that  the  present  Memoir  would  be  incomplete  without  a 
reference  to  those  personal  characteristics  upon  which  the 
work  of  his  life  hinged  and  which  can  only  be  very  faintly 
gathered  from  his  Autobiography. 

He  was  of  medium  stature  and  not  powerfully  built :  as 
he  advanced  in  years  he  stooped  a  good  deal.  His  hands 
were  large-boned  and  well-formed.  His  constitution  was 
remarkably  sound.  At  no  period  in  his  life  does  he  seem  to 
have  taken  the  least  interest  in  athletic  sports  or  competitions, 
but  he  was  a  very  active  pedestrian  and  could  endure  a 
great  deal  of  fatigue.  He  was  by  no  means  wanting  in 
physical  courage,  and  on  various  occasions,  especially  in 
boating  expeditions,  he  ran  considerable  risks.  In  debate 
and  controversy  he  had  great  self-reliance,  and  was  abso- 
lutely fearless.  His  eye-sight  was  peculiar,  and  required 
correction  by  spectacles  the  lenses  of  which  were  ground  to 
peculiar  curves  according  to  formulae  which  he  himself  in- 
vestigated :  with  these  spectacles  he  saw  extremely  well,  and 
he  commonly  carried  three  pairs,  adapted  to  different 
distances  :  he  took  great  interest  in  the  changes  that  took 
place  in  his  eye-sight,  and  wrote  several  Papers  on  the 
subject.  In  his  later  years  he  became  somewhat  deaf,  but 
not  to  the  extent  of  serious  personal  inconvenience. 

A.  B.  i 


GEORGE   BIDDELL  AIRY. 


The  ruling  feature  of  his  character  was  undoubtedly  Order. 
From  the  time  that  he  went  up  to  Cambridge  to  the  end  of 
his  life  his  system  of  order  was  strictly  maintained.  He 
wrote  his  autobiography  up  to  date  soon  after  he  had  taken 
his  degree,  and  made  his  first  will  as  soon  as  he  had  any 
money  to  leave.  His  accounts  were  perfectly  kept  by  double 
entry  throughout  his  life,  and  he  valued  extremely  the  order 
of  book-keeping:  this  facility  of  keeping  accounts  was  very 
useful  to  him.  He  seems  not  to  have  destroyed  a  document 
of  any  kind  whatever :  counterfoils  of  old  cheque-books,  notes 
for  tradesmen,  circulars,  bills,  and  correspondence  of  all  sorts 
were  carefully  preserved  in  the  most  complete  order  from  the 
time  that  he  went  to  Cambridge ;  and  a  huge  mass  they 
formed.  To  a  high  appreciation  of  order  he  attributed  in  a 
great  degree  his  command  of  mathematics,  and  sometimes 
spoke  of  mathematics  as  nothing  more  than  a  system  of  order 
carried  to  a  considerable  extent.  In  everything  he  was 
methodical  and  orderly,  and  he  had  the  greatest  dread  of 
disorder  creeping  into  the  routine  work  of  the  Observatory, 
even  in  the  smallest  matters.  As  an  example,  he  spent  a 
whole  afternoon  in  writing  the  word  "  Empty  "  on  large  cards, 
to  be  nailed  upon  a  great  number  of  empty  packing  boxes, 
because  he  noticed  a  little  confusion  arising  from  their  getting 
mixed  with  other  boxes  containing  different  articles ;  and  an 
assistant  could  not  be  spared  for  this  work  without  with- 
drawing him  from  his  appointed  duties.  His  arrangement  of 
the  Observatory  correspondence  was  excellent  and  elaborate : 
probably  no  papers  are  more  easy  of  reference  than  those 
arranged  on  his  system.  His  strict  habits  of  order  made  him 
insist  very  much  upon  detail  in  his  business  with  others,  and 
the  rigid  discipline  arising  out  of  his  system  of  order  made 
his  rule  irksome  to  such  of  his  subordinates  as  did  not 
conform  readily  to  it :  but  the  efficiency  of  the  Observatory 
unquestionably  depended  mainly  upon  it.  As  his  powers 
failed  with  age  the  ruling  passion  for  order  assumed  a  greater 
prominence;  and  in  his  last  days  he  seemed  to  be  more 


PERSONAL  SKETCH. 


anxious  to  put  letters  which  he  received  into  their  proper 
place  for  reference  than  even  to  master  their  contents. 

His  nature  was  eminently  practical,  and  any  subject  which 
had  a  distinctly  practical  object,  and  could  be  advanced  by 
mathematical  investigation,  possessed  interest  for  him.  And 
his  dislike  of  mere  theoretical  problems  and  investigations 
was  proportionately  great.  He  was  continually  at  war  with 
some  of  the  resident  Cambridge  mathematicians  on  this 
subject.  Year  after  year  he  criticised  the  Senate  House 
Papers  and  the  Smith's  Prize  Papers  question  by  question 
very  severely  :  and  conducted  an  interesting  and  acrimonious 
private  correspondence  with  Professor  Cayley  on  the  same 
subject.  His  great  mathematical  powers  and  his  command 
of  mathematics  are  sufficiently  evidenced  by  the  numerous 
mathematical  treatises  of  the  highest  order  which  he  published, 
a  list  of  which  is  appended  to  this  biography.  But  a  very 
important  feature  of  his  investigations  was  the  thoroughness 
of  them.  He  was  never  satisfied  with  leaving  a  result  as 
a  barren  mathematical  expression.  He  would  reduce  it,  if 
possible,  to  a  practical  and  numerical  form,  at  any  cost  of 
labour :  and  would  use  any  approximations  which  would 
conduce  to  this  result,  rather  than  leave  the  result  in  an  un- 
fruitful condition.  He  never  shirked  arithmetical  work :  the 
longest  and  most  laborious  reductions  had  no  terrors  for  him, 
and  he  was  remarkably  skilful  with  the  various  mathematical 
expedients  for  shortening  and  facilitating  arithmetical  work 
of  a  complex  character.  This  power  of  handling  arithmetic 
was  of  great  value  to  him  in  the  Observatory  reductions  and 
in  the  Observatory  work  generally.  He  regarded  it  as  a  duty 
to  finish  off  his  work,  whatever  it  was,  and  the  writer  well 
remembers  his  comment  on  the  mathematics  of  one  of  his  old 
friends,  to  the  effect  that  "  he  was  too  fond  of  leaving  a  result 
in  the  form  of  three  complex  equations  with  three  unknown 
quantities."  To  one  who  had  known,  in  some  degree,  of  the 
enormous  quantity  of  arithmetical  work  which  he  had  turned 
out,  and  the  unsparing  manner  in  which  he  had  devoted 

I 2 


GEORGE   BIDDELL  AIRY. 


himself  to    it,   there    was   something   very   pathetic   in    his 
discovery,  towards  the  close  of  his  long  life,  "that  the  figures' 
would  not  add  up." 

His  energy  and  business  capacity  were  remarkable.  He 
was  made  for  work  and  could  not  long  be  happy  without  it. 
Whatever  subject  he  was  engaged  upon,  he  kept  his  object 
clearly  in  view,  and  made  straight  for  it,  aiming  far  more 
at  clearness  and  directness  than  at  elegance  of  periods  or 
symmetry  of  arrangement.  He  wrote  his  letters  with  great 
ease  and  rapidity:  and  having  written  them  he  very  rarely 
had  occasion  to  re-write  them,  though  he  often  added  inser- 
tions and  interlineations,  even  in  the  most  important  official 
letters.  Without  this  it  would  have  been  impossible  for  him 
to  have  turned  out  the  enormous  quantity  of  correspondence 
that  he  did.  He  never  dictated  letters,  and  only  availed  him- 
self of  clerical  assistance  in  matters  of  the  most  ordinary 
routine.  In  his  excursions,  as  in  his  work,  he  was  always 
energetic,  and  could  not  endure  inaction.  Whatever  there 
was  of  interest  in  the  places  that  he  visited  he  examined 
thoroughly  and  without  delay,  and  then  passed  on.  And  he 
thus  accomplished  a  great  deal  in  a  short  vacation.  His 
letters  written  to  his  wife,  while  he  was  on  his  excursions,  are 
very  numerous  and  characteristic,  and  afford  ample  proofs  of 
his  incessant  energy  and  activity  both  of  body  and  mind. 
They  are  not  brilliantly  written,  for  it  was  not  in  his  nature 
to  write  for  effect,  and  he  would  never  give  himself  the 
trouble  to  study  the  composition  of  his  letters,  but  they  are 
straight-forward,  clear,  and  concise,  and  he  was  never  at  a 
loss  for  suitable  language  to  express  his  ideas.  He  had  a 
wonderful  capacity  for  enjoyment :  the  subjects  that  chiefly 
interested  him  were  scenery,  architecture,  and  antiquities,  but 
everything  novel  or  curious  had  an  interest  for  him.  He 
made  several  journeys  to  the  Continent,  but  by  far  the 
greater  number  of  his  excursions  were  made  in  England  and 
Scotland,  and  there  were  few  parts  of  the  country  which  he 
had  not  visited.  He  was  very  fond  of  the  Lake  District  of 


PERSONAL   SKETCH.  5 

Cumberland,  and  visited  it  very  frequently,  and  each  time 
that  he  went  there  the  same  set  of  views  had  an  eternal 
freshness  for  him,  and  he  wrote  long  descriptions  of  the 
scenery  and  effects  with  the  same  raptures  as  if  he  had  seen 
it  for  the  first  time.  Many  of  his  letters  were  written  from 
Playford,  a  village  in  a  beautiful  part  of  Suffolk,  a  few  miles 
from  Ipswich.  Here  he  had  a  small  property,  and  generally 
stayed  there  for  a  short  time  once  or  twice  a  year.  He  was 
extremely  fond  of  this  country,  and  was  never  tired  of 
repeating  his  walks  by  the  well-known  lanes  and  footpaths. 
And,  as  in  Cumberland,  the  Suffolk  country  had  an  eternal 
freshness  and  novelty  for  him.  Wherever  he  went  he  was 
indefatigable  in  keeping  up  his  acquaintance  with  his  nu- 
merous friends  and  his  letters  abound  in  social  reminiscences. 

His  memory  was  singularly  retentive.  It  was  much 
remarked  at  school  in  his  early  days,  and  in  the  course 
of  his  life  he  had  stored  up  in  his  memory  an  incredible 
quantity  of  poetry,  ballads,  and  miscellaneous  facts  and 
information  of  all  sorts,  which  was  all  constantly  ready 
and  at  his  service.  It  is  almost  needless  to  add  that  his 
memory  was  equally  accurate  and  extensive  in  matters 
connected  with  science  or  business. 

His  independence  of  character  was  no  doubt  due  to  and 
inseparable  from  his  great  powers.  The  value  of  his  scientific 
work  greatly  depended  upon  his  self-reliance  and  indepen- 
dence of  thought.  And  in  the  heavy  work  of  remodelling 
the  Observatory  it  was  a  very  valuable  quality.  This  same 
self-reliance  made  him  in  his  latter  years  apt  to  draw 
conclusions  too  confidently  and  hastily  on  subjects  which 
he  had  taken  up  more  as  a  pastime  than  as  work.  But 
whatever  he  touched  he  dealt  with  ably  and  in  the  most 
fearless  truthseeking  manner,  and  left  original  and  vigorous 
opinions. 

He  had  a  remarkably  well-balanced  mind,  and  a  simplicity 
of  nature  that  appeared  invulnerable.  No  amount  of  hero- 
worship  seemed  to  have  the  least  effect  upon  him.  And 


GEORGE   BIDDELL  AIRY. 


from  a  very  early  time  he  was  exposed  to  a  great  deal 
of  it.  His  mind  was  incessantly  engaged  on  investigations 
of  Nature,  and  this  seems  to  have  been  with  him,  as  has 
been  the  case  with  others,  a  preserving  influence.  This 
simplicity  of  character  he  retained  throughout  his  life.  At 
the  same  time  he  was  sensible  and  shrewd  in  his  money 
matters  and  attentive  to  his  personal  interests.  And  his 
practical  good  sense  in  the  general  affairs  of  life,  combined 
with  his  calm  and  steady  consideration  of  points  submitted 
to  him,  made  his  advice  very  valuable.  This  was  especially 
recognized  by  his  own  and  his  wife's  relations,  who  consulted 
him  on  many  occasions  and  placed  the  fullest  confidence  in 
his  absolute  sense  of  justice  as  well  as  in  his  wise  counsel. 
He  was  extremely  liberal  in  proportion  to  his  means,  and 
gave  away  money  to  a  large  extent  to  all  who  had  any  claim 
upon  him.  But  he  was  not  in  any  sense  reckless,  and  kept  a 
most  cautious  eye  on  his  expenses.  He  was  not  indifferent 
to  the  honours  which  he  received  in  the  scientific  world,  but 
he  does  not  appear  to  have  sought  them  in  any  way,  and  he 
certainly  did  not  trouble  himself  about  them. 

His  courtesy  was  unfailing :  no  amount  of  trouble  could 
shake  it.  Whether  it  was  the  Secretary  of  the  Admiralty,  or 
a  servant  girl  wanting  her  fortune  told :  whether  a  begging- 
letter  for  money,  or  miscellaneous  invitations :  all  had  their 
answer  in  the  most  clear  and  courteous  language.  But  he 
would  not  grant  personal  interviews  when  he  could  avoid  it : 
they  took  up  too  much  of  his  time.  His  head  was  so  clear 
that  he  never  seemed  to  want  for  the  clearest  and  most  direct 
language  in  expressing  his  meaning,  and  his  letters  are 
models  of  terseness. 

In  all  his  views  and  opinions  he  was  strongly  liberal.  At 
Cambridge  at  an  early  date  he  was  one  of  the  83  members  of 
the  Senate  who  supported  the  application  to  permit  the 
granting  of  medical  degrees  without  requiring  an  expression 
of  assent  to  the  religious  doctrines  of  the  Church  of  England. 
And  in  1868  he  declined  to  sign  a  petition  against  the  abo- 


PERSONAL  SKETCH. 


lition  of  religious  declarations  required  of  persons  admitted 
to  Fellowships  or  proceeding  to  the  degree  of  M.A.  And  he 
was  opposed  to  every  kind  of  narrowness  and  exclusiveness. 
When  he  was  appointed  to  the  post  of  Astronomer  Royal,  he 
stipulated  that  he  should  not  be  asked  to  vote  in  any  political 
election.  But  all  his  views  were  in  the  liberal  direction.  He 
was  a  great  reader  of  theology  and  church  history,  and  as 
regarded  forms  of  worship  and  the  interpretation  of  the 
Scriptures,  he  treated  them  with  great  respect,  but  from 
the  point  of  view  of  a  freethinking  layman.  In  the  Preface 
to  his  "  Notes  on  the  Earlier  Hebrew  Scriptures "  he  says, 
"In  regard  to  the  general  tone  of  these  notes,  I  will  first 
remark  that  I  have  nothing  to  say  on  the  subject  of  verbal 
inspiration.  With  those  who  entertain  that  doctrine,  I  can 
have  nothing  in  common.  Nor  do  I  recognize,  in  the  pro- 
fessedly historical  accounts,  any  other  inspiration  which  can 
exempt  them  from  the  severest  criticism  that  would  be 
applicable  to  so-called  profane  accounts,  written  under  the 
same  general  circumstances,  and  in  the  same  countries."  And 
his  treatment  of  the  subject  in  the  "  Notes "  shews  how 
entirely  he  took  a  rationalistic  view  of  the  whole  question. 
He  also  strongly  sided  with  Bishop  Colenso  in  his  fearless 
criticism  of  the  Pentateuch,  though  he  dissented  from  some 
of  his  conclusions.  But  he  was  deeply  imbued  with  the  spirit 
of  religion  and  reflected  much  upon  it.  His  whole  correspond- 
ence conveys  the  impression  of  the  most  sterling  integrity 
and  high-mindedness,  without  a  trace  of  affectation.  In  no 
letter  does  there  appear  a  shadow  of  wavering  on  matters  of 
principle,  whether  in  public  or  private  matters,  and  he  was 
very  clear  and  positive  in  his  convictions. 

The  great  secret  of  his  long  and  successful  official  career 
was  that  he  was  a  good  servant  and  thoroughly  understood 
his  position.  He  never  set  himself  in  opposition  to  his 
masters,  the  Admiralty.  He  never  hesitated  to  ask  the 
Admiralty  for  what  he  thought  right,  whether  in  the  way 
of  money  grants  for  various  objects,  or  for  occasional 


GEORGE   BIDDELL  AIRY. 

permission  to  give  his  services  to  scientific  matters  not 
immediately  connected  with  the  Observatory.  Sometimes 
the  Admiralty  refused  his  requests,  and  he  felt  this  very 
keenly,  but  he  was  far  too  busy  and  energetic  to  trouble 
himself  about  such  little  slights,  and  cheerfully  accepted 
the  situation.  What  was  refused  by  one  Administration 
was  frequently  granted  by  another;  and  in  the  meantime 
he  was  always  ready  to  give  his  most  zealous  assistance 
in  any  matter  that  was  officially  brought  before  him.  This 
cheerful  readiness  to  help,  combined  with  his  great  ability 
and  punctuality  in  business  matters,  made  him  a  very 
valuable  servant,  and  speaking  generally  he  had  the  con- 
fidence of  the  Admiralty  in  a  remarkable  degree.  In  many 
of  his  Reports  to  the  Board  of  Visitors  he  speaks  gratefully 
of  the  liberality  of  the  Admiralty  in  forwarding  scientific 
progress  and  research.  In  matters  too  which  are  perhaps 
of  minor  importance  from  the  high  stand-point  of  science, 
but  which  are  invaluable  in  the  conduct  of  an  important 
business  office,  such  for  example  as  estimates  and  official 
correspondence,  he  was  orderly  and  punctual  in  the  highest 
degree.  And,  what  is  by  no  means  unimportant,  he  possessed 
an  excellent  official  style  in  correspondence,  combined  with 
great  clearness  of  expression.  His  entire  honesty  of  purpose, 
and  the  high  respect  in  which  he  was  held  both  at  home  and 
abroad,  gave  great  weight  to  his  recommendations. 

With  regard  to  his  habits  while  he  resided  at  the 
Observatory,  his  custom  was  to  work  in  his  official  room 
from  9  to  about  2.30,  though  in  summer  he  was  frequently 
at  work  before  breakfast.  He  then  took  a  brisk  walk,  and 
dined  at  about  3.30.  This  early  hour  had  been  prescribed 
and  insisted  upon  by  his  physician,  Dr  Haviland  of  Cam- 
bridge, in  whom  he  had  great  confidence.  He  ate  heartily, 
though  simply  and  moderately,  and  slept  for  about  an  hour 
after  dinner.  He  then  had  tea,  and  from  about  7  to  10  he 
worked  in  the  same  room  with  his  family.  He  would  never 
retire  to  a  private  room,  and  regarded  the  society  of  his  family 


PERSONAL   SKETCH. 


as  highly  beneficial  in  "  taking  the  edge  off  his  work."  His 
powers  of  abstraction  were  remarkable :  nothing  seemed  to 
disturb  him ;  neither  music,  singing,  nor  miscellaneous  con- 
versation. He  would  then  play  a  game  or  two  at  cards, 
read  a  few  pages  of  a  classical  or  historical  book,  and  retire 
at  ii.  On  Sundays  he  attended  morning  service  at  church, 
and  in  the  evening  read  a  few  prayers  very  carefully  and 
impressively  to  his  whole  household.  He  was  very  hospitable, 
and  delighted  to  receive  his  friends  in  a  simple  ^and  natural 
way  at  his  house.  In  this  he  was  most  admirably  aided  by 
his  wife,  whose  grace  and  skill  made  everything  pleasant  to 
their  guests.  But  he  avoided  dinner-parties  as  much  as 
possible — they  interfered  too  much  with  his  work — and  with 
the  exception  of  scientific  and  official  dinners  he  seldom 
dined  away  from  home.  His  tastes  were  entirely  domestic, 
and  he  was  very  happy  in  his  family.  With  his  natural  love 
of  work,  and  with  the  incessant  calls  upon  him,  he  would 
soon  have  broken  down,  had  it  not  been  for  his  system  of 
regular  relaxation.  Two  or  three  times  a  year  he  took  a 
holiday:  generally  a  short  run  of  a  week  or  ten  days  in 
the  spring,  a  trip  of  a  month  or  thereabouts  in  the  early 
autumn,  and  about  three  weeks  at  Playford  in  the  winter. 
These  trips  were  always  conducted  in  the  most  active 
manner,  either  in  constant  motion  from  place  to  place,  or 
in  daily  active  excursions.  This  system  he  maintained  with 
great  regularity,  and  from  the  exceeding  interest  and  enjoy- 
ment that  he  took  in  these  trips  his  mind  was  so  much 
refreshed  and  steadied  that  he  always  kept  himself  equal 
to  his  work. 

Airy  seems  to  have  had  a  strong  bent  in  the  direction  of 
astronomy  from  his  youth,  and  it  is  curious  to  note  how  well 
furnished  he  was,  by  the  time  that  he  became  Astronomer 
Royal,  both  with  astronomy  in  all  its  branches,  and  with  the 
kindred  sciences  so  necessary  for  the  practical  working  and 
improvement  of  it.  At  the  time  that  he  went  to  Cambridge 
Physical  Astronomy  was  greatly  studied  there  and  formed  a 


IO  GEORGE  BIDDELL  AIRY. 

most  important  part  of  the  University  course.  He  eagerly 
availed  himself  of  this,  and  mastered  the  Physical  Astronomy 
in  the  most  thorough  manner,  as  was  evidenced  by  his  Papers 
collected  in  his  "  Mathematical  Tracts,"  his  investigation  of 
the  Long  Inequality  of  the  Earth  and  Venus,  and  many 
other  works.  As  Plumian  Professor  he  had  charge  of  the 
small  Observatory  at  Cambridge,  where  he  did  a  great  deal 
of  the  observing  and  reduction  work  himself,  and  became 
thoroughly  versed  in  the  practical  working  of  an  Observatory. 
The  result  of  this  was  immediately  seen  in  the  improved 
methods  which  he  introduced  at  Greenwich,  and  which  were 
speedily  imitated  at  other  Observatories.  Optics  and  the 
Undulatory  Theory  of  Light  had  been  very  favourite  subjects 
with  him,  and  he  had  written  and  lectured  frequently  upon 
them.  In  the  construction  of  the  new  and  powerful  telescopes 
and  other  optical  instruments  required  from  time  to  time 
this  knowledge  was  very  essential,  for  in  its  instrumental 
equipment  the  Greenwich  Observatory  was  entirely  re- 
modelled during  his  tenure  of  office.  And  in  many  of  the 
matters  referred  to  him,  as  for  instance  that  of  the  Light- 
houses, a  thorough  knowledge  of  Optics  was  most  valuable. 
He  had  made  a  great  study  of  the  theory  and  construction 
of  clocks,  and  this  knowledge  was  invaluable  to  him  at 
Greenwich  in  the  establishment  of  new  and  more  accurate 
astronomical  clocks,  and  especially  in  the  improvement  of 
chronometers.  He  had  carefully  studied  the  theory  of 
pendulums,  and  had  learned  how  to  use  them  in  his  ex- 
periments in  the  Cornish  mines.  This  knowledge  he  after- 
wards utilized  very  effectively  at  the  Harton  Pit  in  comparing 
the  density  of  the  Earth's  crust  with  its  mean  density ;  and 
it  was  very  useful  to  him  in  connection  with  geodetic  surveys 
and  experiments  on  which  he  was  consulted.  And  his 
mechanical  knowledge  was  useful  in  almost  everything. 

The  subjects  (outside  those  required  for  his  professional 
work)  in  which  he  took  most  interest  were  Poetry,  History, 
Theology,  Antiquities,  Architecture,  and  Engineering.  He 


PERSONAL  SKETCH.  II 


was  well  acquainted  with  standard  English  poetry,  and  had 
committed  large  quantities  to  memory,  which  he  frequently 
referred  to  as  a  most  valuable  acquisition  and  an  ever-present 
relief  and  comfort  to  his  mind.  History  and  Theology  he 
had  studied  as  opportunity  offered,  and  without  being  widely 
read  in  them  he  was  much  at  home  with  them,  and  his 
powerful  memory  made  the  most  of  what  he  did  read.  An- 
tiquities and  Architecture  were  very  favourite  subjects  with 
him.  He  had  visited  most  of  the  camps  and  castles  in  the 
United  Kingdom  and  was  never  tired  of  tracing  their  con- 
nection with  ancient  military  events :  and  he  wrote  several 
Papers  on  this  subject,  especially  those  relating  to  the  Roman 
Invasions  of  Britain.  Ecclesiastical  Architecture  he  was  very 
fond  of:  he  had  visited  nearly  all  the  cathedrals  and  principal 
churches  in  England,  and  many  on  the  Continent,  and  was 
most  enthusiastic  on  their  different  styles  and  merits :  his 
letters  abound  in  critical  remarks  on  them.  He  was  ex- 
tremely well  versed  in  mechanics,  and  in  the  principles  and 
theory  of  construction,  and  took  the  greatest  interest  in  large 
engineering  works.  This  led  to  much  communication  with 
Stephenson,  Brunei,  and  other  Engineers,  who  consulted  him 
freely  on  the  subject  of  great  works  on  which  they  were 
engaged :  in  particular  he  rendered  much  assistance  in  con- 
nection with  the  construction  of  the  Britannia  Bridge  over 
the  Menai  Straits.  There  were  various  other  subjects  which 
he  read  with  much  interest  (Geology  in  particular),  but  he 
made  no  study  of  Natural  History,  and  knew  very  little  about 
it  beyond  detached  facts.  His  industry  was  untiring,  and  in 
going  over  his  books  one  by  one  it  was  very  noticeable  how 
large  a  number  of  them  were  feathered  with  his  paper 
"marks,"  shewing  how  carefully  he  had  read  them  and 
referred  to  them.  His  nature  was  essentially  cheerful,  and 
literature  of  a  witty  and  humourous  character  had  a  great 
charm  for  him.  He  was  very  fond  of  music  and  knew  a 
great  number  of  songs;  and  he  was  well  acquainted  with  the 


12  GEORGE   BIDDELL  AIRY. 

theory  of  music:  but  he  was  no  performer.  He  did  not 
sketch  freehand  but  made  excellent  drawings  with  his  Camera 
Lucida. 

At  the  time  when  he  took  his  degree  (1823)  and  for  many 
years  afterwards  there  was  very  great  activity  of  scientific 
investigation  and  astronomical  enterprise  in  England.  And, 
as  in  the  times  of  Flamsteed  and  Halley,  the  earnest  zeal  of 
men  of  science  occasionally  led  to  much  controversy  and 
bitterness  amongst  them.  Airy  was  by  no  means  exempt 
from  such  controversies.  He  was  a  man  of  keen  sensitive- 
ness, though  it  was  combined  with  great  steadiness  of  temper, 
and  he  never  hesitated  to  attack  theories  and  methods  that 
he  considered  to  be  scientifically  wrong.  This  led  to  dif- 
ferences with  Ivory,  Challis,  South,  Cayley,  Archibald  Smith, 
and  others  ;  but  however  much  he  might  differ  from  them  he 
was  always  personally  courteous,  and  the  disputes  generally 
went  no  farther  than  as  regarded  the  special  matter  in 
question.  Almost  all  these  controversial  discussions  were 
carried  on  openly,  and  were  published  in  the  Athenaeum,  the 
Philosophical  Magazine,  or  elsewhere ;  for  he  printed  nearly 
everything  that  he  wrote,  and  was  very  careful  in  the  selection 
of  the  most  suitable  channels  for  publication.  He  regarded  it 
as  a  duty  to  popularize  as  much  as  possible  the  work  done  at 
the  Observatory,  and  to  take  the  public  into  his  confidence. 
And  this  he  effected  by  articles  communicated  to  newspapers, 
lectures,  numerous  Papers  written  for  scientific  societies, 
reports,  debates,  and  critiques. 

His  strong  constitution  and  his  regular  habits,  both  of 
work  and  exercise,  are  sufficient  explanation  of  the  good 
health  which  in  general  he  enjoyed.  Not  but  what  he  had 
sharp  touches  of  illness  from  time  to  time.  At  one  period  he 
suffered  a  good  deal  from  an  attack  of  eczema,  and  at  another 
from  a  varicose  vein  in  his  leg,  and  he  was  occasionally 
troubled  with  severe  colds.  But  he  bore  these  ailments  with 
great  patience  and  threw  them  off  in  course  of  time.  He  was 


PERSONAL   SKETCH.  13 


happy  in  his  marriage  and  in  his  family,  and  such  troubles 
and  distresses  as  were  inevitable  he  accepted  calmly  and 
quietly.  In  his  death,  as  in  his  life,  he  was  fortunate :  he  had 
no  long  or  painful  illness,  and  he  was  spared  the  calamity  of 
aberration  of  intellect,  the  saddest  of  all  visitations. 


CHAPTER   II. 

FROM  HIS  BIRTH  TO  HIS  TAKING  HIS  B.A.  DEGREE 
AT  CAMBRIDGE. 

FROM  JULY  2/TH  1801  TO  JANUARY  ISTH  1823. 

GEORGE  BIDDELL  AIRY  was  born  at  Alnwick  in  North- 
umberland on  July  27th  1801.  His  father  was  William  Airy 
of  Luddington  in  Lincolnshire,  the  descendant  of  a  long  line 
of  Airys  who  have  been  traced  back  with  a  very  high  degree 
of  probability  to  a  family  of  that  name  which  was  settled  at 
Kentmere  in  Westmorland  in  the  I4th  century.  A  branch  of 
this  family  migrated  to  Pontefract  in  Yorkshire,  where  they 
seem  to  have  prospered  for  many  years,  but  they  were  involved 
in  the  consequences  of  the  Civil  Wars,  and  one  member  of 
the  family  retired  to  Ousefleet  in  Yorkshire.  His  grandson 
removed  to  Luddington  in  Lincolnshire,  where  his  descendants 
for  several  generations  pursued  the  calling  of  small  farmers. 
George  Biddell  Airy's  mother,  Ann  Airy,  was  the  daughter  of 
George  Biddell,  a  well-to-do  farmer  in  Suffolk. 

William  Airy,  the  father  of  George  Biddell  Airy,  was  a 
man  of  great  activity  and  strength,  and  of  prudent  and  steady 
character.  When  a  young  man  he  became  foreman  on  a 
farm  in  the  neighbourhood  of  Luddington,  and  laid  by  his 
earnings  in  summer  in  order  to  educate  himself  in  winter. 
For  a  person  in  his  rank,  his  education  was  unusually  good, 
in  matters  of  science  and  in  English  literature.  But  at  the 
age  of  24  he  grew  tired  of  country  labour,  and  obtained  a 
post  in  the  Excise.  After  serving  in  various  Collections  he 
was  appointed  Collector  of  the  Northumberland  Collection 


FROM   BIRTH   TO   B.A.   DEGREE.  15 

on  the  1 5th  August  1800,  and  during  his  service  there  his 
eldest  son  George  Biddell  Airy  was  born.  The  time  over 
which  his  service  as  Officer  and  Supervisor  extended  was 
that  in  which  smuggling  rose  to  a  very  high  pitch,  and 
in  which  the  position  of  Excise  Officer  was  sometimes 
dangerous.  He  was  remarkable  for  his  activity  and  boldness 
in  contests  with  smugglers,  and  made  many  seizures.  Ann 
Airy,  the  mother  of  George  Biddell  Airy,  was  a  woman  of 
great  natural  abilities  both  speculative  and  practical,  kind  as 
a  neighbour  and  as  head  of  a  family,  and  was  deeply  loved 
and  respected.  The  family  consisted  of  George  Biddell, 
Elizabeth,  William,  and  Arthur  who  died  young. 

William  Airy  was  appointed  to  Hereford  Collection  on 
22nd  October  1802,  and  removed  thither  shortly  after.  He 
stayed  at  Hereford  till  he  was  appointed  to  Essex  Collection 
on  28th  February  1810,  and  during  this  time  George  Biddell 
was  educated  at  elementary  schools  in  writing,  arithmetic, 
and  a  little  Latin.  He  records  of  himself  that  he  was  not  a 
favourite  with  the  schoolboys,  for  he  had  very  little  animal 
vivacity  and  seldom  joined  in  active  play  with  his  school- 
fellows. But  in  the  proceedings  of  the  school  he  was  suc- 
cessful, and  was  a  favourite  with  his  master. 

On  the  appointment  of  William  Airy  to  Essex  Collection, 
the  family  removed  to  Colchester  on  April  5th  1810.  Here 
George  Biddell  was  first  sent  to  a  large  school  in  Sir  Isaac's 
Walk,  then  kept  by  Mr  Byatt  Walker,  and  was  soon  noted  for 
his  correctness  in  orthography,  geography,  and  arithmetic. 
He  evidently  made  rapid  progress,  for  on  one  occasion  Mr 
Walker  said  openly  in  the  schoolroom  how  remarkable  it  was 
that  a  boy  10  years  old  should  be  the  first  in  the  school.  At 
this  school  he  stayed  till  the  end  of  1813  and  thoroughly 
learned  arithmetic  (from  Walkingame's  book),  book-keeping 
by  double  entry  (on  which  knowledge  throughout  his  life 
he  set  a  special  value),  the  use  of  the  sliding  rule  (which 
knowledge  also  was  specially  useful  to  him  in  after  life), 
mensuration  and  algebra  (from  Bonnycastle's  books).  He 


1 6  GEORGE   BIDDELL  AIRY. 

also  studied  grammar  in  all  its  branches,  and  geography, 
and  acquired  some  knowledge  of  English  literature,  beginning 
with  that  admirable  book  The  Speaker,  but  it  does  not  appear 
that  Latin  and  Greek  were  attended  to  at  this  school.  He 
records  that  at  this  time  he  learned  an  infinity  of  snatches 
of  songs,  small  romances,  &c.,  which  his  powerful  memory 
retained  most  accurately  throughout  his  life.  He  was  no 
hand  at  active  play:  but  was  notorious  for  his  skill  in  con- 
structing guns  for  shooting  peas  and  arrows,  and  other 
mechanical  contrivances.  At  home  he  relates  that  he  picked 
up  a  wonderful  quantity  of  learning  from  his  father's  books. 
He  read  and  remembered  much  poetry  from  such  standard 
authors  as  Milton,  Pope,  Gay,  Gray,  Swift,  &c.,  which  was 
destined  to  prove  in  after  life  an  invaluable  relaxation  for  his 
mind.  But  he  also  studied  deeply  an  excellent  Cyclopaedia 
called  a  Dictionary  of  Arts  and  Sciences  in  three  volumes 
folio,  and  learned  from  it  much  about  ship-building,  naviga- 
tion, fortification,  and  many  other  subjects. 

During  this  period  his  valuable  friendship  with  his  uncle 
Arthur  Biddell  commenced.  Arthur  Biddell  was  a  prosperous 
farmer  and  valuer  at  Playford  near  Ipswich.  He  was  a  well- 
informed  and  able  man,  of  powerful  and  original  mind, 
extremely  kind  and  good-natured,  and  greatly  respected 
throughout  the  county.  In  the  Autobiography  of  George 
Biddell  Airy  he  states  as  follows : 

"  I  do  not  remember  precisely  when  it  was  that  I  first 
visited  my  uncle  Arthur  Biddell.  I  think  it  was  in  a  winter  : 
certainly  as  early  as  the  winter  of  1812 — 13.  Here  I  found  a 
friend  whose  society  I  could  enjoy,  and  I  entirely  appreciated 
and  enjoyed  the  practical,  mechanical,  and  at  the  same  time 
speculative  and  enquiring  talents  of  Arthur  Biddell.  He  had 
a  library  which,  for  a  person  in  middle  life,  may  be  called 
excellent,  and  his  historical  and  antiquarian  knowledge  was 
not  small.  After  spending  one  winter  holiday  with  him,  it 
easily  came  to  pass  that  I  spent  the  next  summer  holiday 
with  him  :  and  at  the  next  winter  holiday,  finding  that  there 


FROM    BIRTH   TO   B.A.    DEGREE.  17 

was  no  precise  arrangement  for  my  movements,  I  secretly 
wrote  him  a  letter  begging  him  to  come  with  a  gig  to  fetch 
me  home  with  him  :  he  complied  with  my  request,  giving  no 
hint  to  my  father  or  mother  of  my  letter :  and  from  that 
time,  one-third  of  every  year  was  regularly  spent  with  him 
till  I  went  to  College.  How  great  was  the  influence  of  this 
on  my  character  and  education  I  cannot  tell.  It  was  with 
him  that  I  became  acquainted  with  the  Messrs  Ransome, 
W.  Cubitt  the  civil  engineer  (afterwards  Sir  W.  Cubitt), 
Bernard  Barton,  Thomas  Clarkson  (the  slave-trade  aboli- 
tionist), and  other  persons  whose  acquaintance  I  have  valued 
highly.  It  was  also  with  him  that  I  became  acquainted  with 
the  works  of  the  best  modern  poets,  Scott,  Byron,  Campbell, 
Hogg,  and  others :  as  also  with  the  Waverley  Novels  and 
other  works  of  merit." 

In  1813  William  Airy  lost  his  appointment  of  Collector 
of  Excise  and  was  in  consequence  very  much  straitened 
in  his  circumstances.  But  there  was  no  relaxation  in  the 
education  of  his  children,  and  at  the  beginning  of  1814 
George  Biddell  was  sent  to  the  endowed  Grammar  School 
at  Colchester,  then  kept  by  the  Rev.  E.  Crosse,  and  remained 
there  till  the  summer  of  1819,  when  he  went  to  College. 
The  Autobiography  proceeds  as  follows  : 

"  I  became  here  a  respectable  scholar  in  Latin  and  Greek, 
to  the  extent  of  accurate  translation,  and  composition  of 
prose  Latin :  in  regard  to  Latin  verses  I  was  I  think  more 
defective  than  most  scholars  who  take  the  same  pains,  but 
I  am  not  much  ashamed  of  this,  for  I  entirely  despise  the 
system  of  instruction  in  verse  composition. 

"  My  father  on  some  occasion  had  to  go  to  London  and 
brought  back  for  me  a  pair  of  1 2-inch  globes.  They  were 
invaluable  to  me.  The  first  stars  which  I  learnt  from  the 
celestial  globe  were  a  Lyrae,  a  Aquilae,  a  Cygni :  and  to  this 
time  I  involuntarily  regard  these  stars  as  the  birth-stars  of 
my  astronomical  knowledge.  Having  somewhere  seen  a 
description  of  a  Gunter's  quadrant,  I  perceived  that  I  could 

A.   B.  2 


1 8  GEORGE   BIDDELL  AIRY. 

construct  one  by  means  of  the  globe  :  my  father  procured 
for  me  a  board  of  the  proper  shape  with  paper  pasted  on 
it,  and  on  this  I  traced  the  lines  of  the  quadrant. 

"  My  command  of  geometry  was  tolerably  complete,  and 
one  way  in  which  I  frequently  amused  myself  was  by  making 
paper  models  (most  carefully  drawn  in  outline)  which  were 
buttoned  together  without  any  cement  or  sewing.  Thus  I 
made  models,  not  only  of  regular  solids,  regularly  irregular 
solids,  cones  cut  in  all  directions  so  as  to  shew  the  conic 
sections,  and  the  like,  but  also  of  six-gun  batteries,  intrench- 
ments  and  fortresses  of  various  kinds  &c. 

"  From  various  books  I  had  learnt  the  construction  of  the 
steam-engine :  the  older  forms  from  the  Dictionary  of  Arts 
and  Sciences ;  newer  forms  from  modern  books.  The  newest 
form  however  (with  the  sliding  steam  valve)  I  learnt  from  a 
6-horse  engine  at  Bawtrey's  brewery  (in  which  Mr  Keeling 
the  father  of  my  schoolfellow  had  acquired  a  partnership).  I 
frequently  went  to  look  at  this  engine,  and  on  one  occasion 
had  the  extreme  felicity  of  examining  some  of  its  parts  when 
it  was  opened  for  repair. 

"  In  the  mean  time  my  education  was  advancing  at 
Playford.  The  first  record,  I  believe,  which  I  have  of  my 
attention  to  mechanics  there  is  the  plan  of  a  threshing- 
machine  which  I  drew.  But  I  was  acquiring  valuable  infor- 
mation of  all  kinds  from  the  Encyclopaedia  Londinensis,  a 
work  which  without  being  high  in  any  respect  is  one  of  the 
most  generally  useful  that  I  have  seen.  But  I  well  remember 
one  of  the  most  important  steps  that  I  ever  made.  I  had 
tried  experiments  with  the  object-glass  of  an  opera-glass  and 
was  greatly  astonished  at  the  appearance  of  the  images  of 
objects  seen  through  the  glass  under  different  conditions. 
By  these  things  my  thoughts  were  turned  to  accurate  optics, 
and  I  read  with  care  Rutherford's  Lectures,  which  my  uncle 
possessed.  The  acquisition  of  an  accurate  knowledge  of  the 
effect  of  optical  constructions  was  one  of  the  most  charming 
attainments  that  I  ever  reached.  Long  before  I  went  to 


FROM   BIRTH   TO   B.A.   DEGREE.  19 

College  I  understood  the  action  of  the  lenses  of  a  telescope 
better  than  most  opticians.  I  also  read  with  great  zeal 
Nicholson's  Dictionary  of  Chemistry,  and  occasionally  made 
chemical  experiments  of  an  inexpensive  kind  :  indeed  I  grew 
so  fond  of  this  subject  that  there  was  some  thought  of 
apprenticing  me  to  a  chemist.  I  also  attended  to  surveying 
and  made  a  tolerable  survey  and  map  of  my  uncle's  farm. 

"  At  school  I  was  going  on  successfully,  and  distinguished 
myself  particularly  by  my  memory.  It  was  the  custom  for 
each  boy  once  a  week  to  repeat  a  number  of  lines  of  Latin  or 
Greek  poetry,  the  number  depending  very  much  on  his  own 
choice.  I  determined  on  repeating  100  every  week,  and  I 
never  once  fell  below  that  number  and  was  sometimes  much 
above  it.  It  was  no  distress  to  me,  and  great  enjoyment. 
At  Michaelmas  1816  I  repeated  2394  lines,  probably  without 
missing  a  word.  I  do  not  think  that  I  was  a  favourite  with 
Mr  Crosse,  but  he  certainly  had  a  high  opinion  of  my  powers 
and  expressed  this  to  my  father.  My  father  entertained  the 
idea  of  sending  me  to  College,  which  Mr  Crosse  recom- 
mended :  but  he  heard  from  some  college  man  that  the 
expense  would  be  £200  a  year,  and  he  laid  aside  all  thoughts 
of  it. 

"The  farm  of  Playford  Hall  was  in  1813  or  1814  hired  by 
Thomas  Clarkson,  the  slave-trade  abolitionist.  My  uncle 
transacted  much  business  for  him  (as  a  neighbour  and  friend) 
in  the  management  of  the  farm  &c.  for  a  time,  and  they 
became  very  intimate.  My  uncle  begged  him  to  examine 
me  in  Classical  knowledge,  and  he  did  so,  I  think,  twice.  He 
also  gave  some  better  information  about  the  probable  ex- 
penses &c.  at  College.  The  result  was  a  strong  recommen- 
dation by  my  uncle  or  through  my  uncle  that  I  should  be 
sent  to  Cambridge,  and  this  was  adopted  by  my  father.  I 
think  it  likely  that  this  was  in  1816. 

"In  December  1816,  Dealtry's  Fluxions  was  bought  for  me, 
and  I  read  it  and  understood  it  well.  I  borrowed  Hutton's 
Course  of  Mathematics  of  old  Mr  Ransome,  who  had  come  to 

2 2 


2O  GEORGE   BIDDELL   AIRY. 

reside  at  Greenstead  near  Colchester,  and  read  a  good  deal 
of  it. 

"About  Ladyday  1817  I  began  to  read  mathematics  with 
Mr  Rogers  (formerly,  I  think,  a  Fellow  of  Sidney  College,  and 
an  indifferent  mathematician  of  the  Cambridge  school),  who 
had  succeeded  a  Mr  Tweed  as  assistant  to  Mr  Crosse  in  the 
school.  I  went  to  his  house  twice  a  week,  on  holiday  after- 
noons. I  do  not  remember  how  long  I  received  lessons  from 
him,  but  I  think  to  June  1818.  This  course  was  extremely 
valuable  to  me,  not  on  account  of  Mr  Rogers's  abilities  (for  I 
understood  many  things  better  than  he  did)  but  for  its  train- 
ing me  both  in  Cambridge  subjects  and  in  the  Cambridge 
accurate  methods  of  treating  them.  I  went  through  Euclid 
(as  far  as  usually  read),  Wood's  Algebra,  Wood's  Mechanics, 
.Vince's  Hydrostatics,  Wood's  Optics,  Trigonometry  (in  a 
geometrical  treatise  and  also  in  Woodhouse's  algebraical 
form),  Fluxions  to  a  good  extent,  Newton's  Principia  to  the 
end  of  the  9th  section.  This  was  a  large  quantity,  but  I 
read  it  accurately  and  understood  it  perfectly,  and  could 
write  out  any  one  of  the  propositions  which  I  had  read  in 
the  most  exact  form.  My  connexion  with  Mr  Rogers  was 
terminated  by  his  giving  me  notice  that  he  could  not  under- 
take to  receive  me  any  longer :  in  fact  I  was  too  much  for 
him.  I  generally  read  these  books  in  a  garret  in  our  house 
in  George  Lane,  which  was  indefinitely  appropriated  to  my 
brother  and  myself.  I  find  that  I  copied  out  Vince's  Conic 
Sections  in  February  1819.  The  first  book  that  I  copied  was 
the  small  geometrical  treatise  on  Trigonometry,  in  May 
1817:  to  this  I  was  urged  by  old  Mr  Ransome,  upon  my 
complaining  that  I  could  not  purchase  the  book :  and  it  was 
no  bad  lesson  of  independence  to  me." 

During  the  same  period  1817 — 1819  he  was  occupied 
at  school  on  translations  into  blank  verse  from  the  ^neid 
and  Iliad,  and  read  through  the  whole  of  Sophocles  very 
carefully. 

The  Classical  knowledge  which  he  thus  gained  at  school 


FROM   BIRTH   TO   B.A.    DEGREE.  21 

and  subsequently  at  Cambridge  was  sound,  and  he  took 
great  pleasure  in  it :  throughout  his  life  he  made  a  practice 
of  keeping  one  or  other  of  the  Classical  Authors  at  hand  for 
occasional  relaxation.  He  terminated  his  schooling  in  June 
1819.  Shortly  afterwards  his  father  left  Colchester  and  went 
to  reside  at  Bury  St  Edmund's.  The  Autobiography  pro- 
ceeds as  follows  : 

"  Mr  Clarkson  was  at  one  time  inclined  to  recommend  me 
to  go  to  St  Peter's  College  (which  had  been  much  enriched 
by  a  bequest  from  a  Mr  Gisborne).  But  on  giving  some 
account  of  me  to  his  friend  Mr  James  D.  Hustler,  tutor  of 
Trinity  College,  Mr  Hustler  urged  upon  him  that  I  was 
exactly  the  proper  sort  of  person  to  go  to  Trinity  College. 
And  thus  it  was  settled  (mainly  by  Mr  Clarkson)  that  I 
should  be  entered  at  Trinity  College.  I  think  that  I  was 
sent  for  purposely  from  Colchester  to  Playford,  and  on 
March  6th,  1819,  I  rode  in  company  with  Mr  Clarkson  from 
Playford  to  Sproughton  near  Ipswich  to  be  examined  by  the 
Rev.  Mr  Rogers,  incumbent  of  Sproughton,  an  old  M.A.  of 
Trinity  College :  and  was  examined,  and  my  certificate  duly 
sent  to  Mr  Hustler :  and  I  was  entered  on  Mr  Hustler's  side 
as  Sizar  of  Trinity  College. 

"In  the  summer  of  1819  I  spent  some  time  at  Playford. 
On  July  27th,  1819  (my  birthday,  18  years  old),  Mr  Clarkson 
invited  me  to  dinner,  to  meet  Mr  Charles  Musgrave,  Fellow 
of  Trinity  College,  who  was  residing  for  a  short  time  at 
Grundisburgh,  taking  the  church  duty  there  for  Dr  Ramsden, 
the  Rector.  It  was  arranged  that  I  should  go  to  Grun- 
disburgh the  next  day  (I  think)  to  be  examined  in  mathe- 
matics by  Mr  Musgrave.  I  went  accordingly,  and  Mr 
Musgrave  set  before  me  a  paper  of  questions  in  geometry, 
algebra,  mechanics,  optics,  &c.  ending  with  the  first  proposi- 
tion of  the  Principia.  I  knew  nothing  more  about  my 
answers  at  the  time  :  but  I  found  long  after  that  they  excited 
so  much  admiration  that  they  were  transmitted  to  Cam- 
bridge (I  forget  whether  to  Mr  Musgrave's  brother,  a  Fellow 


22  GEORGE   BIDDELL  AIRY. 

of  Trinity  College  and  afterwards  Archbishop  of  York,  or 
to  Mr  Peacock,  afterwards  Dean  of  Ely)  and  were  long 
preserved. 

"  The  list  of  the  Classical  subjects  for  ,the  first  year  in 
Trinity  College  was  transmitted  to  me,  as  usual,  by  Mr 
Hustler.  They  were — The  Hippolytus  of  Euripides,  the 
3rd  Book  of  Thucydides,  and  the  2nd  Philippic  of  Cicero. 
These  I  read  carefully  and  noted  before  going  up.  Mr 
Hustler's  family  lived  in  Bury;  and  I  called  on  him  and 
saw  him  in  October,  introduced  by  Mr  Clarkson.  On  the 
morning  of  October  i8th,  1819, 1  went  on  the  top  of  the  coach 
to  Cambridge,  knowing  nobody  there  but  Mr  Hustler,  but 
having  letters  of  introduction  from  Mr  Charles  Musgrave  to 
Professor  Sedgwick,  Mr  Thomas  Musgrave,  and  Mr  George 
Peacock,  all  Fellows  of  Trinity  College. 

"  I  was  set  down  at  the  Hoop,  saw  Trinity  College  for  the 
first  time,  found  Mr  Hustler,  was  conducted  by  his  servant  to 
the  robe-maker's,  where  I  was  invested  in  the  cap  and  blue 
gown,  and  after  some  further  waiting  was  installed  into 
lodgings  in  Bridge  Street.  At  4  o'clock  I  went  to  the 
College  Hall  and  was  introduced  by  Mr  Hustler  to  several 
undergraduates,  generally  clever  men,  and  in  the  evening  I 
attended  Chapel  in  my  surplice  (it  being  St  Luke's  day) 
and  witnessed  that  splendid  service  of  which  the  occasional 
exhibition  well  befits  the  place. 

"  As  soon  as  possible,  I  called  on  Mr  Peacock,  Mr  Mus- 
grave, and  Professor  Sedgwick.  By  all  I  was  received  with 
great  kindness:  my  examination  papers  had  been  sent  to  them, 
and  a  considerable  reputation  preceded  me.  Mr  Peacock  at 
once  desired  that  I  would  not  consider  Mr  C.  Musgrave's 
letter  as  an  ordinary  introduction,  but  that  I  would  refer  to 
him  on  all  occasions.  And  I  did  so  for  several  years,  and 
always  received  from  him  the  greatest  assistance  that  he 
could  give.  I  think  that  I  did  not  become  acquainted  with 
Mr  Whewell  till  the  next  term,  when  I  met  him  at  a  break- 
fast party  at  Mr  Peacock's.  Mr  Peacock  at  once  warned  me 


FROM    BIRTH   TO   B.A.    DEGREE.  23 

to  arrange  for  taking  regular  exercise,  and  prescribed  a  walk 
of  two  hours  every  day  before  dinner :  a  rule  to  which  I 
attended  regularly,  and  to  which  I  ascribe  the  continuance  of 
good  general  health. 

"I  shewed  Mr  Peacock  a  manuscript  book  which  contained 
a  number  of  original  Propositions  which  I  had  investigated. 
These  much  increased  my  reputation  (I  really  had  sense 
enough  to  set  no  particular  value  on  it)  and  I  was  soon 
known  by  sight  to  almost  everybody  in  the  University.  A 
ridiculous  little  circumstance  aided  in  this.  The  former  rule 
of  the  University  (strictly  enforced)  had  been  that  all 
students  should  wear  drab  knee-breeches :  and  I,  at  Mr 
Clarkson's  recommendation,  was  so  fitted  up.  The  struggle 
between  the  old  dress  and  the  trowsers  customary  in  society 
was  still  going  on  but  almost  terminated,  and  I  was  one  of 
the  very  few  freshmen  who  retained  the  old  habiliments. 
This  made  me  in  some  measure  distinguishable :  however  at 
the  end  of  my  first  three  terms  I  laid  these  aside. 

"  The  College  Lectures  began  on  Oct.  22  :  Mr  Evans  at  9 
on  the  Hippolytus,  and  Mr  Peacock  at  10  on  Euclid  (these 
being  the  Assistant  Tutors  on  Mr  Hustler's  side) :  and  then  I 
felt  myself  established. 

"  I  wrote  in  a  day  or  two  to  my  uncle  Arthur  Biddell,  and 
I  received  from  him  a  letter  of  the  utmost  kindness.  He 
entered  gravely  on  the  consideration  of  my  prospects,  my 
wants,  &c. :  and  offered  at  all  times  to  furnish  me  with 
money,  which  he  thought  my  father's  parsimonious  habits 
might  make  him  unwilling  to  do.  I  never  had  occasion  to 
avail  myself  of  this  offer:  but  it  was  made  in  a  way  which 
in  no  small  degree  strengthened  the  kindly  feelings  that  had 
long  existed  between  us. 

"I  carefully  attended  the  lectures,  taking  notes  as  appeared 
necessary.  In  Mathematics  there  were  geometrical  problems, 
algebra,  trigonometry  (which  latter  subjects  the  lectures  did 
not  reach  till  the  terms  of  1820).  Mr  Peacock  gave  me  a  copy 
of  Lacroix's  Differential  Calculus  as  translated  by  himself 


24  GEORGE    BIDDELL  AIRY. 


and  Herschel  arid  Babbage,  and  also  a  copy  of  their  Ex- 
amples. At  this  time,  the  usfe  of  Differential  Calculus  was 
just  prevailing  over  that  of  Fluxions  (which  I  had  learnt).  I 
betook  myself  to  it  with  great  industry.  I  also  made  myself 
master  of  the  theories  of  rectangular  coordinates  and  some  of 
the  differential  processes  applying  to  them,  which  only  a  few 
of  the  best  of  the  university  mathematicians  then  wholly 
possessed.  In  Classical  subjects  I  read  the  Latin  (Seneca's) 
and  English  Hippolytus,  Racine's  Phedre  (which  my  sister 
translated  for  me),  and  all  other  books  to  which  I  was 
referred,  Aristotle,  Longinus,  Horace,  Bentley,  Dawes  &c., 
made  verse  translations  of  the  Greek  Hippolytus,  and  was 
constantly  on  the  watch  to  read  what  might  be  advan- 
tageous. 

"  Early  in  December  Mr  Hustler  sent  for  me  to  say  that 
one  of  the  Company  of  Fishmongers,  Mr  R.  Sharp,  had  given 
to  Mr  John  H.  Smyth,  M.P.  for  Norwich,  the  presentation  to  a 
small  exhibition  of  £20  a  year,  which  Mr  Smyth  had  placed 
in  Mr  Hustler's  hands,  and  which  Mr  Hustler  immediately 
conferred  on  me.  This  was  my  first  step  towards  pecuniary 
independence.  I  retained  this  exhibition  till  I  became  a 
Fellow  of  the  College. 

"I  stayed  at  Cambridge  during  part  of  the  winter  vacation, 
and  to  avoid  expense  I  quitted  my  lodgings  and  went  for  a 
time  into  somebody's  rooms  in  the  Bishop's  Hostel.  (It  is 
customary  for  the  tutors  to  place  students  in  rooms  when 
their  right  owners  are  absent.)  I  took  with  me  Thucydides 
and  all  relating  to  it,  and  read  the  book,  upon  which  the  next 
term's  lectures  were  to  be  founded,  very  carefully.  The  latter 
part  of  the  vacation  I  spent  at  Bury,  where  I  began  with  the 
assistance  of  my  sister  to  pick  up  a  little  French :  as  I  per- 
ceived that  it  was  absolutely  necessary  for  enabling  me  to 
read  modern  mathematics. 

"  During  a  part  of  the  time  I  employed  myself  in  writing 
out  a  paper  on  the  geometrical  interpretation  of  the  alge- 
braical expression  V—  i.  I  think  that  the  original  suggestion 


FROM    BIRTH   TO   B.A.   DEGREE.  2$ 

of  perpendicular  line  came  from  some  book  (I  do  not  re- 
member clearly),  and  I  worked  it  out  in  several  instances 
pretty  well,  especially  in  De  Moivre's  Theorem.  I  had 
spoken  of  it  in  the  preceding  term  to  Mr  Peacock  and  he 
encouraged  me  to  work  it  out.  The  date  at  the  end  is  1820, 
January  21.  When  some  time  afterwards  I  spoke  of  it  to 
Mr  Hustler,  he  disapproved  of  my  employing  my  time  on 
such  speculations.  About  the  last  day  of  January  I  returned 
to  Cambridge,  taking  up  my  abode  in  my  former  lodgings.  I 
shewed  my  paper  on  V— I  to  Mr  Peacock,  who  was  much 
pleased  with  it  and  shewed  it  to  Mr  Whewell  and  others. 

"  On  February  I  I  commenced  two  excellent  customs. 
The  first  was  that  I  always  had  upon  my  table  a  quire  of 
large-sized  scribbling-paper  sewn  together :  and  upon  this 
paper  everything  was  entered  :  translations  into  Latin  and 
out  of  Greek,  mathematical  problems,  memoranda  of  every 
kind  (the  latter  transferred  when  necessary  to  the  subsequent 
pages),  and  generally  with  the  date  of  the  day.  This  is  a 
most  valuable  custom.  The  other  was  this  :  as  I  perceived 
that  to  write  Latin  prose  well  would  be  useful  to  me,  I  wrote 
a  translation  of  English  into  Latin  every  day.  However 
much  pressed  I  might  be  with  other  business,  I  endeavoured 
to  write  at  least  three  or  four  words,  but  if  possible  I  wrote  a 
good  many  sentences. 

"  I  may  fix  upon  this  as  the  time  when  my  daily  habits 
were  settled  in  the  form  in  which  they  continued  for  several 
years.  I  rose  in  time  for  the  chapel  service  at  7.  It  was  the 
College  regulation  that  every  student  should  attend  Chapel 
four  mornings  and  four  evenings  (Sunday  being  one  of  each) 
in  every  week :  and  in  this  I  never  failed.  After  chapel 
service  I  came  to  my  lodgings  and  breakfasted.  At  9  I  went 
to  College  lectures,  which  lasted  to  n.  Most  of  my  con- 
temporaries, being  intended  for  the  Church,  attended  also 
divinity  lectures :  but  I  never  did.  I  then  returned,  put  my 
lecture  notes  in  order,  wrote  my  piece  of  Latin  prose,  and 
then  employed  myself  on  the  subject  which  I  was  reading  for 


26  GEORGE   BIDDELL  AIRY. 

the  time :  usually  taking  mathematics  at  this  hour.  At  2  or 
a  little  sooner  I  went  out  for  a  long  walk,  usually  4  or  5 
miles  into  the  country:  sometimes  if  I  found  companions  I 
rowed  on  the  Cam  (a  practice  acquired  rather  later).  A  little 
before  4  I  returned,  and  at  4  went  to  College  Hall.  After 
dinner  I  lounged  till  evening  chapel  time,  ^  past  5,  and 
returning  about  6  I  then  had  tea.  Then  I  read  quietly, 
usually  a  classical  subject,  till  1 1  ;  and  I  never,  even  in  the 
times  when  I  might  seem  most  severely  pressed,  sat  up  later. 
"  From  this  time  to  the  close  of  the  annual  examination 
(beginning  of  June)  I  remained  at  Cambridge,  stopping  there 
through  the  Easter  Vacation.  The  subjects  of  the  mathe- 
matical lectures  were  ordinary  algebra  and  trigonometry :  but 
Mr  Peacock  always  had  some  private  problems  of  a  higher 
class  for  me,  and  saw  me  I  believe  every  day.  The  subjects 
of  the  Classical  lectures  were,  the  termination  of  Hippolytus, 
the  book  of  Thucydides  and  the  oration  of  Cicero.  In 
mathematics  I  read  Whewell's  Mechanics,  then  just  published 
(the  first  innovation  made  in  the  Cambridge  system  of 
Physical  Sciences  for  many  years) :  and  I  find  in  my  scrib- 
bling-paper  notes,  integrals,  central  forces,  Finite  Differences, 
steam-engine  constructions  and  powers,  plans  of  bridges, 
spherical  trigonometry,  optical  calculations  relating  to  the 
achromatism  of  eye-pieces  and  achromatic  object-glasses  with 
lenses  separated,  mechanical  problems,  Transit  of  Venus, 
various  problems  in  geometrical  astronomy  (I  think  it  was  at 
this  time  that  Mr  Peacock  had  given  me  a  copy  of  Wood- 
house's  Astronomy  1st  Edition),  the  rainbow,  plans  for  anemo- 
meter and  for  a  wind-pumping  machine,  clearing  lunars,  &c., 
with  a  great  number  of  geometrical  problems.  I  remark  that 
my  ideas  on  the  Differential  Calculus  had  not  acquired  on 
some  important  points  the  severe  accuracy  which  they  acquired 
in  a  few  months.  In  Classics  I  read  the  Persae  of  ^Eschylus, 
Greek  and  Roman  history  very  much  (Mitford,  Hooke, 
Ferguson)  and  the  books  of  Thucydides  introductory  to  that 
of  the  lecture  subject  (the  3rd):  and  attended  to  Chronology. 


FROM    BIRTH    TO   B.A.   DEGREE.  27 

On  the  scribbling-paper  are  verse-translations  from  Euripides, 
careful  prose-translations  from  Thucydides,  maps,  notes  on 
points  of  grammar  &c.  I  have  also  little  MS.  books  with 
abundant  notes  on  all  these  subjects:  I  usually  made  a  little 
book  when  I  pursued  any  subject  in  a  regular  way. 

"  On  May  1st  Mr  Dobree,  the  head  lecturer,  sent  for  me  to 
say  that  he  appointed  me  head-lecturer's  Sizar  for  the  next 
year.  The  stipend  of  this  office  was  £10,  a  sum  upon  which 
I  set  considerable  value  in  my  anxiety  for  pecuniary  inde- 
pendence: but  it  was  also  gratifying  to  me  as  shewing  the 
way  in  which  I  was  regarded  by  the  College  authorities. 

"On  Wednesday,  May  24th,  1820,  the  examination  began. 
I  was  anxious  about  the  result  of  the  examination,  but  only 
in  such  a  degree  as  to  make  my  conduct  perfectly  steady  and 
calm,  and  to  prevent  me  from  attempting  any  extraordinary 
exertion. 

"  When  the  Classes  were  published  the  first  Class  of  the 
Freshman's  Year  (alphabetically  arranged,  as  is  the  custom) 
stood  thus:  Airy,  Boileau,  Childers,  Drinkwater,  Field,  Iliff, 
Malkin,  Myers,  Romilly,  Strutt,  Tate,  Winning.  It  was  soon 
known  however  that  I  was  first  of  the  Class.  It  was 
generally  expected  (and  certainly  by  me)  that,  considering 
how  great  a'  preponderance  the  Classics  were  understood,  in 
the  known  system  of  the  College,  to  have  in  determining  the 
order  of  merit,  Field  would  be  first.  However  the  number  of 
marks  which  Field  obtained  was  about  1700,  and  that  which 
I  obtained  about  1900.  No  other  competitor,  I  believe,  was 
near  us." — In  a  letter  to  Airy  from  his  College  Tutor, 
Mr  J.  D.  Hustler,  there  is  the  following  passage :  "  It  is  a 
matter  of  extreme  satisfaction  to  me  that  in  the  late  exami- 
nation you  stood  not  only  in  the  First  Class  but  first  of  the 
first.  I  trust  that  your  future  exertions  and  success  will  be 
commensurate  with  this  honourable  beginning." 

"  Of  the  men  whom  I  have  named,  Drinkwater  (Bethune) 
was  afterwards  Legal  Member  of  the  Supreme  Court  of 
India,  Field  was  afterwards  Rector  of  Reepham,  Romilly 


28  GEORGE   BIDDELL  AIRY. 

(afterwards  Lord  Rorpilly)  became  Solicitor-General,  Strutt 
(afterwards  Lord  Belper)  became  M.P.  for  Derby  and  First 
Commissioner  of  Railways,  Tate  was  afterwards  master  of 
Richmond  Endowed  School,  Childers  was  the  father  of 
Childers  who  was  subsequently  First  Lord  of  the  Admiralty. 

"  I  returned  to  Bury  immediately.  While  there,  some 
students  (some  of  them  men  about  to  take  their  B.A.  degree 
at  the  next  January)  applied  to  me  to  take  them  as  pupils, 
but  I  declined.  This  year  of  my  life  enabled  me  to  under- 
stand how  I  stood  among  men.  I  returned  to  Cambridge 
about  July  nth.  As  a  general  rule,  undergraduates  are  not 
allowed  to  reside  in  the  University  during  the  Long  Vacation. 
I  believe  that  before  I  left,  after  the  examination,  I  had  made 
out  that  I  should  be  permitted  to  reside:  or  I  wrote  to  Mr 
Hustler.  I  applied  to  Mr  Hustler  to  be  lodged  in  rooms  in 
College :  and  was  put,  first  into  rooms  in  Bishop's  Hostel, 
and  subsequently  into  rooms  in  the  Great  Court. 

"The  first  affair  that  I  had  in  College  was  one  of  disap- 
pointment by  no  means  deserving  the  importance  which  it 
assumed  in  my  thoughts.  I  had  been  entered  a  Sizar,  but  as 
the  list  of  Foundation  Sizars  was  full,  my  dinners  in  Hall 
were  paid  for.  Some  vacancies  had  arisen  :  and  as  these 
were  to  be  filled  up  in  order  of  merit,  I  expected  one :  and  in 
my  desire  for  pecuniary  independence  I  wished  for  it  very 
earnestly.  However,  as  in  theory  all  of  the  first  class  were 
equal,  and  as  there  were  some  Sizars  in  it  senior  in  entrance 
to  me,  they  obtained  places  first :  and  I  was  not  actually 
appointed  till  after  the  next  scholarship  examination  (Easter 
1821).  However  a  special  arrangement  was  made,  allowing 
me  (I  forget  whether  others)  to  sit  at  the  Foundation-Sizars' 
table  whenever  any  of  the  number  was  absent :  and  in  conse- 
quence I  received  practically  nearly  the  full  benefits. 

"  Mr  Peacock,  who  was  going  out  for  the  Vacation,  allowed 
me  access  to  his  books.  I  had  also  (by  the  assistance  of 
various  Fellows,  who  all  treated  me  with  great  kindness, 
almost  to  a  degree  of  respect)  command  of  the  University 


FROM   BIRTH   TO   B.A.    DEGREE.  29 

Library  and  Trinity  Library :  and  spent  this  Long  Vacation, 
like  several  others,  very  happily  indeed. 

"The  only  non-mathematical  subjects  of  the  next  exami- 
nation were  The  Gospel  of  St  Luke3  Paley's  Evidences,  and 
Paley's  Moral  and  Political  Philosophy.  Thus  my  time  was 
left  more  free  to  mathematics  and  to  general  classics  than 
last  year.  I  now  began  a  custom  which  I  maintained  for 
some  years.  Generally  I  read  mathematics  in  the  morning, 
and  classics  for  lectures  in  the  afternoon :  but  invariably  I 
began  at  to  o'clock  in  the  evening  to  read  with  the  utmost 
severity  some  standard  classics  (unconnected  with  the  lec- 
tures) and  at  1 1  precisely  I  left  off  and  went  to  bed.  I  con- 
tinued my  daily  translations  into  Latin  prose  as  before. 

"On  August  24th,  1820,  Rosser,  a  man  of  my  own  year, 
engaged  me  as  private  tutor,  paying  at  the  usual  rate  (£14 
for  a  part  of  the  Vacation,  and  £14  for  a  term):  and  immedi- 
ately afterwards  his  friend  Bedingfield  did  the  same.  This 
occupied  two  hours  every  day,  and  I  felt  that  I  was  now  com- 
pletely earning  my  own  living.  I  never  received  a  penny 
from  my  friends  after  this  time. 

"  I  find  on  my  scribbling-paper  various  words  which  shew 
that  in  reading  Poisson  I  was  struggling  with  French  words. 
There  are  also  Finite  Differences  and  their  Calculus,  Figure 
of  the  Earth  (force  to  the  center),  various  Attractions  (some 
evidently  referring  to  Maclaurin's),  Integrals,  Conic  Sections, 
Kepler's  Problem,  Analytical  Geometry,  D'Alembert's 
Theorem,  Spherical  Aberration,  Rotations  round  three  axes 
(apparently  I  had  been  reading  Euler),  Floating  bodies, 
Evolute  of  Ellipse,  Newton's  treatment  of  the  Moon's  Varia- 
tion. I  attempted  to  extract  something  from  Vince's  Astro- 
nomy on  the  physical  explanation  of  Precession :  but  in 
despair  of  understanding  it,  and  having  made  out  an  expla- 
nation for  myself  by  the  motion  round  three  axes,  I  put 
together  a  little  treatise  (Sept.  10,  1820)  which  with  some 
corrections  and  additions  was  afterwards  printed  in  my 
Mathematical  Tracts.  On  Sept.  I4th  I  bought  Woodhouse's 


30  GEORGE    BIDDELL  AIRY. 

Physical  Astronomy, .and  this,  was  quite  an  epoch  in  my 
mathematical  knowledge.  First,  I  was  compelled  by  the 
process  of  "  changing  the  independent  variable  "  to  examine 
severely  the  logic  of  the  Differential  Calculus.  Secondly,  I 
was  now  able  to  enter  on  the  Theory  of  Perturbations,  which 
for  several  years  had  been  the  desired  land  to  me. 

"At  the  Fellowship  Election  of  Oct.  ist,  Sydney  Walker 
(among  other  persons)  was  elected  Fellow.  He  then  quitted 
the  rooms  in  which  he  had  lived  (almost  the  worst  in  the 
College),  and  I  immediately  took  them.  They  suited  me 
well  and  I  lived  very  happily  in  them  till  I  was  elected 
Scholar.  They  are  small  rooms  above  the  middle  staircase 
on  the  south  side  of  Neville's  Court.  (Mr  Peacock's  rooms 
were  on  the  same  staircase.)  I  had  access  to  the  leads  on 
the  roof  of  the  building  from  one  of  my  windows.  This  was 
before  the  New  Court  was  built :  my  best  window  looked 
upon  the  garden  of  the  College  butler. 

"  I  had  brought  to  Cambridge  the  telescope  which  I  had 
made  at  Colchester,  and  about  this  time  I  had  a  stand  made 
by  a  carpenter  at  Cambridge :  and  I  find  repeated  observa- 
tions of  Jupiter  and  Saturn  made  in  this  October  term. 

"Other  mathematical  subjects  on  my  scribbling-paper  are: 
Geometrical  Astronomy,  Barometers  (for  elevations),  Mac- 
laurin's  Figure  of  the  Earth,  Lagrange's  Theorem,  Integrals, 
Differential  Equations  of  the  second  order,  Particular  Solu- 
tions. In  general  mathematics  I  had  much  discussion  with 
Atkinson  (who  was  Senior  Wrangler,  January  1821),  and  in 
Physics  with  Rosser,  who  was  a  friend  of  Sir  Richard  Phillips, 
a  vain  objector  to  gravitation.  In  Classics  I  read  ^Eschylus 
and  Herodotus. 

"On  October  5th  I  received  notice  from  the  Head  Lecturer 
to  declaim  in  English  with  Winning.  (This  exercise  consists 
in  preparing  a  controversial  essay,  learning  it  by  heart,  and 
speaking  it  in  Chapel  after  the  Thursday  evening's  service.) 
On  October  6th  we  agreed  on  the  subject,  "  Is  natural  differ- 
ence to  be  ascribed  to  moral  or  to  physical  causes  ?  "  I  taking 


FROM   BIRTH   TO   B.A.    DEGREE.  31 

the  latter  side.  I  spoke  the  declamation  (reciting  it  without 
missing  a  word)  on  October  25th.  On  October  26th  I 
received  notice  of  Latin  declamation  with  Myers :  subject 
agreed  on,  "  Utrum  civitati  plus  utilitatis  an  incommodi  affe- 
rant  leges  quae  ad  vitas  privatorum  hominum  ordinandas 
pertinent "  ;  I  took  the  former.  The  declamation  was  recited 
on  November  II,  when  a  curious  circumstance  occurred.  My 
declamation  was  rather  long :  it  was  the  first  Saturday  of 
the  term  on  which  a  declamation  had  been  spoken  :  and  it 
was  the  day  on  which  arrived  the  news  of  the  withdrawal  of 
the  Bill  of  Pains  and  Penalties  against  Queen  Caroline. 
(This  trial  had  been  going  on  through  the  summer,  but  I 
knew  little  about  it.)  In  consequence  the  impatience  of  the 
undergraduates  was  very  great,  and  there  was  such  an  uproar 
of  coughing  &c.  in  the  Chapel  as  probably  was  never  known. 
The  Master  (Dr  Wordsworth,  appointed  in  the  beginning  of 
the  summer  on  the  death  of  Dr  Mansell,  and  to  whom  I  had 
been  indirectly  introduced  by  Mrs  Clarkson)  and  Tutors  and 
Deans  tried  in  vain  to  stop  the  hubbub.  However  I  went 
on  steadily  to  the  end,  not  at  all  frightened.  On  the  Monday 
the  Master  sent  for  me  to  make  a  sort  of  apology  in  the 
name  of  the  authorities,  and  letters  to  the  Tutors  were  read 
at  the  Lectures,  and  on  the  whole  the  transaction  was  nowise 
disagreeable  to  me. 

"On  the  Commemoration  Day,  December  I5th,  I  received 
my  Prize  (Mitford's  Greece)  as  First-Class  man,  after  dinner 
in  the  College  Hall.  After  a  short  vacation  spent  at  Bury 
and  Playford  I  returned  to  Cambridge,  walking  from  Bury 
on  Jan.  22nd,  1821.  During  the  next  term  I  find  in  Mathe- 
matics Partial  Differential  Equations,  Tides,  Sound,  Calculus 
of  Variations,  Composition  of  rotary  motions,  Motion  in  resist- 
ing medium,  Lhuillier's  theorem,  Brightness  of  an  object  as 
seen  through  a  medium  with  any  possible  law  of  refraction 
(a  good  investigation),  star-reductions,  numerical  calculations 
connected  with  them,  equilibrium  of  chain  under  centripetal 
force  (geometrically  treated,  as  an  improvement  upon  Whe- 


32  GEORGE   BIDDELL  AIRY. 

well's  algebraical  method),  investigation  of  the  magnitude  of 
attractive  forces  of  glass,  &c.,  -required  to  produce  refraction. 
I  forget  about  Mathematical  Lectures ;  but  I  have  an  impres- 
sion that  I  regularly  attended  Mr  Peacock's  lectures,  and 
that  he  always  set  me  some  private  problems. 

"  I  attended  Mr  Evans's  lectures  on  St  Luke  :  and  I  find 
many  notes  about  the  history  of  the  Jews,  Cerinthus  and 
various  heresies,  Paley's  Moral  Philosophy,  Paley's  Evidences, 
and  Biblical  Maps :  also  speculations  about  ancient  pronun- 
ciations. 

"For  a  week  or  more  before  the  annual  examination  I  was 
perfectly  lazy.  The  Classes  of  my  year  (Junior  Sophs)  were 
not  published  till  June  11.  It  was  soon  known  that  I  was 
first  with  2000  marks,  the  next  being  Drinkwater  with  1200 
marks.  After  a  short  holiday  at  Bury  and  Playford  I 
returned  to  Cambridge  on  July  i8th,  1821.  My  daily  life 
went  on  as  usual.  I  find  that  in  writing  Latin  I  began 
Cicero  De  Senectute  (retranslating  Melmoth's  translation, 
and  comparing).  Some  time  in  the  Long  Vacation  the  names 
of  the  Prizemen  for  Declamations  were  published :  I  was 
disappointed  that  not  one,  English  or  Latin,  was  assigned 
to  me:  but  it  was  foolish,  for  my  declamations  were  rather 
trumpery. 

"My  former  pupil,  Rosser,  came  again  on  August  I4th. 
On  August  29th  Dr  Blomfield  (afterwards  Bishop  of  London) 
called,  to  engage  me  as  Tutor  to  his  brother  George  Beecher 
Blomfield,  and  he  commenced  attendance  on  Sept.  ist.  With 
these  two  pupils  I  finished  at  the  end  of  the  Long  Vacation  : 
for  the  next  three  terms  I  had  one  pupil,  Gibson,  a  New- 
castle man,  recommended  by  Mr  Peacock,  I  believe,  as  a 
personal  friend  (Mr  Peacock  being  of  Durham). 

"  The  only  classical  subject  appointed  for  the  next  exami- 
nation was  the  5th,  6th  and  /th  Books  of  the  Odyssey :  the 
mathematical  subjects  all  the  Applied  Mathematics  and  New- 
ton. There  was  to  be  however  the  Scholarship  Examination 
(Sizars  being  allowed  to  sit  for  Scholarships  only  in  their 


FROM   BIRTH   TO   B.A.   DEGREE.  33 

3rd  year :  and  the  Scholarship  being  a  kind  of  little  Fellow- 
ship necessary  to  qualify  for  being  a  candidate  for  the  real 
Fellowship). 

"  When  the  October  term  began  Mr  Hustler,  who  usually 
gave  lectures  in  mathematics  to  his  third-year  pupils,  said  to 
me  that  it  was  not  worth  my  while  to  attend  his  lectures,  and 
he  or  Mr  Peacock  suggested  that  Drinkwater,  Myers,  and  I 
should  attend  the  Questionists'  examinations.  The  Ques- 
tionists  are  those  who  are  to  take  the  degree  of  B.A.  in  the 
next  January :  and  it  was  customary,  not  to  give  them 
lectures,  but  three  times  a  week  to  examine  them  by  setting 
mathematical  questions,  as  the  best  method  of  preparing  for 
the  B.A.  examination.  Accordingly  it  was  arranged  that  we 
should  attend  the  said  examinations :  but  when  we  went  the 
Questionists  of  that  year  refused  to  attend.  They  were 
reported  to  be  a  weak  year,  and  we  to  be  a  strong  one :  and 
they  were  disposed  to  take  offence  at  us  on  any  occasion. 
From  some  of  the  scholars  of  our  year  who  sat  at  table  with 
scholars  of  that  year  I  heard  that  they  distinguished  us  as 
'  the  impudent  year,'  '  the  annus  mirabilis,'  &c.  On  this 
occasion  they  pretended  to  believe  that  the  plan  of  our 
attendance  at  the  Questionists'  examinations  had  been  sug- 
gested by  an  undergraduate,  and  no  explanation  was  of  the 
least  use.  So  the  Tutors  agreed  not  to  press  the  matter  on 
them :  and  instead  of  it,  Drinkwater,  Myers,  and  I  went 
three  times  a  week  to  Mr  Peacock's  rooms,  and  he  set  us 
questions.  I  think  that  this  system  was  also  continued  during 
the  next  two  terms  (ending  in  June  1822)  or  part  of  them, 
but  I  am  not  certain. 

"In  August  1821  I  copied  out  a  MS.  on  Optics,  I  think 
from  Mr  Whewell :  on  August  24th  one  on  the  Figure  of  the 
Earth  and  Tides ;  and  at  some  other  time  one  on  the  motion 
of  a  body  round  two  centers  of  force;  both  from  Mr  Whewell. 
On  my  scribbling  paper  I  find— A  problem  on  the  vibrations 
of  a  gig  as  depending  on  the  horse's  step  (like  that  of  a 
pendulum  whose  support  is  disturbed),  Maclaurin's  Attrac- 

A.  B,  3 


34  GEORGE   BIDDELL   AIRY. 

tions,  Effect  of  separating  the  lenses  of  an  achromatic  object- 
glass  (suggested  by  my  old ;  "telescope),  Barlow's  theory  of 
numbers,  and  division  of  the  circle  into  17  parts,  partial 
differentials,  theory  of  eye-pieces,  epicycloids,  Figure  of 
the  Earth,  Time  of  body  in  arc  of  parabola,  Problem  of 
Sound,  Tides,  Refraction  of  Lens,  including  thickness,  &c., 
Ivory's  paper  on  Equations,  Achromatism  of  microscope, 
Capillary  Attraction,  Motions  of  Fluids,  Euler's  principal 

axes,  Spherical  pendulum,  Equation  fr  -^  =  -^ ,  barometer, 

Lunar  Theory  well  worked  out,  ordinary  differential  equa- 
tions, Calculus  of  Variations,  Interpolations  like  Laplace's 
for  Comets,  Kepler's  theorem.  In  September  I  had  my  old 
telescope  mounted  on  a  short  tripod  stand,  and  made  experi- 
ments on  its  adjustments.  I  was  possessed  of  White's  Ephe- 
meris,  and  I  find  observations  of  Jupiter  and  Saturn  in 
October.  I  planned  an  engine  for  describing  ellipses  by  the 

A 

polar  equation  ~ ,  and  tried  to  make  a  micrometer 

I  +  e  cos  0 

with  silk  threads  converging  to  a  point.  Mr  Cubitt  called 
on  Oct.  4  and  Nov.  I  ;  he  was  engaged  in  erecting  a  tread- 
mill at  Cambridge  Gaol,  and  had  some  thoughts  of  sending 
plans  for  the  Cambridge  Observatory,  the  erection  of  which 
was  then  proposed.  On  Nov.  19  I  find  that  I  had  received 
from  Cubitt  a  Nautical  Almanac,  the  first  that  I  had.  On 
Dec.  ill  made  some  experiments  with  Drinkwater :  I  think 
it  was  whirling  a  glass  containing  oil  on  water.  In  Classics 
I  was  chiefly  engaged  upon  Thucydides  and  Homer.  On 
October  6th  I  had  a  letter  from  Charles  Musgrave,  intro- 
ducing Challis,  who  succeeded  me  in  the  Cambridge  Obser- 
vatory in  1836. 

"  At  this  time  my  poor  afflicted  father  was  suffering  much 
from  a  severe  form  of  rheumatism  or  pain  in  the  legs  which 
sometimes  prevented  him  from  going  to  bed  for  weeks 
together. 

"On  the  Commemoration  Day,  Dec.  i8th,  I  received  my 


FROM    BIRTH   TO   B.A.   DEGREE.  35 

prize  as  first-class  man  in  Hall  again.  The  next  day  I 
walked  to  Bury,  and  passed  the  winter  vacation  there  and  at 
Playford. 

"I  returned  to  Cambridge  on  Jan.  24th,  1822.  On  Feb. 
1 2th  I  kept  my  first  Act,  with  great  compliments  from  the 
Moderator,  and  with  a  most  unusually  large  attendance  of 
auditors.  These  disputations  on  mathematics,  in  Latin,  are 
now  discontinued.  On  March  2Oth  I  kept  a  first  Opponency 
against  Sandys.  About  this  time  I  received  Buckle,  a  Trinity 
man  of  my  own  year,  who  was  generally  supposed  to  come 
next  after  Drinkwater,  as  pupil.  On  my  sheets  I  find  inte- 
grals and  differential  equations  of  every  kind,  astronomical 
corrections  (of  which  I  prepared  a  book),  chances,  Englefield's 
comets,  investigation  of  the  brightness  within  a  rainbow, 
proof  of  Clairaut's  theorem  in  one  case,  metacentres,  change 
of  independent  variable  applied  to  a  complicated  case,  gene- 
rating functions,  principal  axes.  On  Apr.  8th  I  intended  to 
write  an  account  of  my  eye  :  I  was  then  tormented  with  a 
double  image,  I  suppose  from  some  disease  of  the  stomach  : 
and  on  May  28th  I  find  by  a  drawing  of  the  appearance  of  a 
lamp  that  the  disease  of  my  eye  continued. 

"  On  Feb.  i  ith  I  gave  Mr  Peacock  a  paper  on  the  alteration 
of  the  focal  length  of  a  telescope  as  directed  with  or  against 
the  Earth's  orbital  motion  (on  the  theory  of  emissions)  which 
was  written  out  for  reading  to  the  Cambridge  Philosophical 
Society  on  Feb.  24th  and  25th.  [This  Society  I  think  was 
then  about  a  year  old.]  On  Feb.  I  my  MS.  on  Precession, 
Solar  Inequality,  and  Nutation,  was  made  complete. 

"  The  important  examination  for  Scholarships  was  now 
approaching.  As  I  have  said,  this  one  opportunity  only  was 
given  to  Sizars  (Pensioners  having  always  two  opportunities 
and  sometimes  three),  and  it  is  necessary  to  be  a  Scholar  in 
order  to  be  competent  to  be  a  candidate  for  a  Fellowship. 
On  Apr.  loth  I  addressed  my  formal  Latin  letter  to  the 
Seniors.  There  were  13  vacancies  and  37  candidates.  The 
election  took  place  on  Apr.  i8th,  1822.  I  was  by  much 

3—2 


36  GEORGE   BIDDELL  AIRY. 

the  first  (which  I  hardly  expected)  and  was  complimented  by 
the  Master  and  others.  Wrote;  the  formal  letter  of  thanks  as 
usual.  I  was  now  entitled  to  claim  better  rooms,  and  I  took 
the  rooms  on  the  ground  floor  on  the  East  sicje  of  the  Queen's 
Gate  of  the  Great  Court.  Even  now  I  think  of  my  quiet 
residence  in  the  little  rooms  above  the  staircase  in  Neville's 
Court  with  great  pleasure.  I  took  possession  of  my  new 
rooms  on  May  27th. 

"The  Annual  Examination  began  on  May  3<Dth.  The 
Classes  were  published  on  June  5th,  when  my  name  was  sepa- 
rated from  the  rest  by  two  lines.  It  was  understood  that  the 
second  man  was  Drinkwater,  and  that  my  number  of  marks 
was  very  nearly  double  of  his.  Having  at  this  time  been  disap- 
pointed of  a  proposed  walking  excursion  into  Derbyshire  with 
a  college  friend,  who  failed  me  at  the  last  moment,  I  walked 
to  Bury  and  spent  a  short  holiday  there  and  at  Playford. 

"I  returned  to  Cambridge  on  July  I2th,  1822.  I  was 
steadily  busy  during  this  Long  Vacation,  but  by  no  means 
oppressively  so :  indeed  my  time  passed  very  happily.  The 
Scholars'  Table  is  the  only  one  in  College  at  which  the 
regular  possessors  of  the  table  are  sure  never  to  see  a  stranger, 
and  thus  a  sort  of  family  intimacy  grows  up  among  the  Scho- 
lars. Moreover  the  Scholars  feel  themselves  to  be  a  privileged 
class  '  on  the  foundation/  and  this  feeling  gives  them  a  sort 
of  conceited  happiness.  It  was  the  duty  of  Scholars  by  turns 
to  read  Grace  after  the  Fellows'  dinner  and  supper,  and  at 
this  time  (1848)  I  know  it  by  heart.  They  also  read  the 
Lessons  in  Chapel  on  week  days  :  but  as  there  was  no  daily 
chapel-service  during  the  summer  vacation,  I  had  not  much 
of  this.  In  the  intimacy  of  which  I  speak  I  became  much 
acquainted  with  Drinkwater,  Buckle,  Rothman,  and  Sutcliffe : 
and  we  formed  a  knot  at  the  table  (first  the  Undergraduate 
Scholars'  table,  and  afterwards  the  Bachelor  Scholars'  table) 
for  several  years.  During  this  Vacation  I  had  for  pupils 
Buckle  and  Gibson. 

"  I  wrote  my  daily  Latin  as  usual,  beginning  with  the 


FROM   BIRTH   TO  B.A.   DEGREE.  37 

retranslation  of  Cicero's  Epistles,  but  I  interrupted  it  from 
Sept.  27th  to  Feb.  8th.  I  believe  it  was  in  this  Vacation,  or 
in  the  October  term,  that  I  began  every  evening  to  read 
Thucydides  very  carefully,  as  my  notes  are  marked  1822  and 
1823.  On  August  27  I  find  that  I  was  reading  Ovid's  Fasti. 

"In  Mathematics  I  find  the  equation  x+y=a,  x?  +y?  =  by 
Caustics,  Calculus  of  Variations,  Partial  Differentials,  Aberra- 
tion of  Light,  Motions  of  Comets,  various  Optical  construc- 
tions computed  with  spherical  aberrations,  Particular  Solu- 
tions, Mechanics  of  Solid  Bodies,  Attractions  of  Shells, 
Chances,  Ivory's  attraction-theorem,  Lunar  Theory  (alge- 
braical), Degrees  across  meridian,  theoretical  refraction, 
Newton's  3rd  Book,  Investigation  of  the  tides  in  a  shallow 
equatoreal  canal,  from  which  I  found  that  there  would  be 
low-water  under  the  moon,  metacentres,  rotation  of  a  solid 
body  round  three  axes,  Attractions  of  Spheroids  of  variable 
density,  finite  differences,  and  complete  Figure  of  the  Earth. 
There  is  also  a  good  deal  of  investigation  of  a  mathematical 
nature  not  connected  with  College  studies,  as  musical  chords, 
organ-pipes,  sketch  for  a  computing  machine  (suggested  by 
the  publications  relating  to  Babbage's),  sketch  of  machine  for 
solving  equations.  In  August  there  is  a  plan  of  a  MS.  on  the 
Differential  Calculus,  which  it  appears  I  wrote  then :  one  on 
the  Figure  of  the  Earth  written  about  August  I5th;  one  on 
Tides,  Sept.  25th  ;  one  on  Newton's  Principia  with  algebraical 
additions,  Nov.  1st.  On  Sept.  6th  and  loth  there  are  Lunar 
Distances  observed  with  Rothman's  Sextant  and  completely 
worked  out ;  for  these  I  prepared  a  printed  skeleton  form,  I 
believe  my  first.  On  December  I3th  there  are  references  to 
books  on  Geology  (Conybeare  and  Phillips,  and  Parkinson) 
which  I  was  beginning  to  study.  On  July  27th,  being  the  day 
on  which  I  completed  my  2ist  year,  I  carefully  did  nothing. 

"  Another  subject  partly  occupied  my  thoughts,  which, 
though  not  (with  reference  to  practical  science)  very  wise, 
yet  gave  me  some  Cambridge  celebrity.  In  July  1819  I 
had  (as  before  mentioned)  sketched  a  plan  for  constructing 


38  GEORGE    BIDDELL  AIRY. 

reflecting  telescopes  with  silvered  glass,  and  had  shewn  it 
afterwards  to  Mr  Peacock.  I  "now  completed  the  theory  of 
this  construction  by  correcting  the  aberrations,  spherical  as 
well  as  chromatic.  On  July  I3th,  1822,  I  drew  up  a  paper 
about  it  for  Mr  Peacock.  He  approved  it  much,  and  in  some 
way  communicated  it  to  Mr  (afterwards  Sir  John)  Herschel. 
I  was  soon  after  introduced  to  Herschel  at  a  breakfast  with 
Mr  Peacock  :  and  he  approved  of  the  scheme  generally.  On 
August  5th  I  drew  up  a  complete  mathematical  paper  for  the 
Cambridge  Philosophical  Society,  which  I  entrusted  to  Mr 
Peacock.  The  aberrations,  both  spherical  and  chromatic,  are 
here  worked  out  very  well.  On  Nov.  25th  it  was  read  at  the 
meeting  of  the  Philosophical  Society,  and  was  afterwards 
printed  in  their  Transactions:  this  was  my  first  printed 
Memoir.  Before  this  time  however  I  had  arranged  to  try 
the  scheme  practically.  Mr  Peacock  had  engaged  to  bear 
the  expense,  but  I  had  no  occasion  to  ask  him.  Partly  (I 
think)  through  Drinkwater,  I  communicated  with  an  optician 
named  Bancks,  in  the  Strand,  who  constructed  the  optical 
part.  I  subsequently  tried  my  telescope,  but  it  would  not 
do.  The  fault,  as  I  had  not  and  have  not  the  smallest  doubt, 
depends  in  some  way  on  the  crystallization  of  the  mercury 
silvering.  It  must  have  been  about  this  time  that  I  was 
introduced  to  Mr  (afterwards  Sir  James)  South,  at  a  party  at 
Mr  Peacock's  rooms.  He  advised  me  to  write  to  Tulley,  a 
well-known  practical  optician,  who  made  me  some  new 
reflectors,  &c.  (so  that  I  had  two  specimens,  one  Gregorian, 
the  other  Cassegrainian).  However  the  thing  failed  practi- 
cally, and  I  was  too  busy  ever  after  to  try  it  again. 

"  During  the  October  term  I  had  no  pupils.  I  kept  my 
second  Act  on  Nov.  6  (opponents  Hamilton,  Rusby,  Field), 
and  an  Opponency  against  Jeffries  on  Nov.  7.  I  attended 
the  Questionists'  Examinations.  I  seem  to  have  lived  a  very 
comfortable  idle  life.  The  Commemoration  Day  was  Dec. 
1 8th,  when  I  received  a  Prize,  and  the  next  day  I  walked  to 
Bury.  On  Jan.  4th,  1823,  I  returned  to  Cambridge,  and 


FROM   BIRTH  TO   B.A.   DEGREE.  39 

until  the  B.A.  Examination  I  read  novels  and  played  cards 
more  than  at  any  other  time  in  College. 

"On  Thursday,  Jan.  9th,  1823,  the  preliminary  classes,  for 
arrangement  of  details  of  the  B.A.  Examination,  were  pub- 
lished. The  first  class,  Airy,  Drinkwater,  Jeffries,  Mason. 
As  far  as  I  remember,  the  rule  was  then,  that  on  certain  days 
the  classes  were  grouped  (in  regard  to  identity  of  questions 

given  to  each  group)  thus:  ist,  \ — -r> ,    -j^-rl ,  &c.,  and  on 


certain  other  days  thus:  \ — . 
'  2nd 


ist 


3rd 


&c.     On  Saturday, 


Jan.  i  ith,  I  paid  fees.  On  Monday,  Jan.  I3th,  the  proceedings 
of  examination  began  by  a  breakfast  in  the  Combination  Room. 
After  this,  Gibson  gave  me  breakfast  every  day,  and  Buckle 
gave  me  and  some  others  a  glass  of  wine  after  dinner.  The 
hours  were  sharp,  the  season  a  cold  one,  and  no  fire  was 
allowed  in  the  Senate  House  where  the  Examination  was 
carried  on  (my  place  was  in  the  East  gallery),  and  altogether 
it  was  a  severe  time. 

"  The  course  of  Examination  was  as  follows  : 

"Monday,  Jan.  I3th.  8  to  9,  printed  paper  of  questions 
by  Mr  Hind  (moderator);  half-past  9  to  II,  questions  given 
orally  ;  I  to  3,  ditto  ;  6  to  9,  paper  of  problems  at  Mr  Hig- 
man's  rooms. 

"  Tuesday,  Jan.  I4th.  8  to  9,  Higman's  paper;  half-past 
9  to  n,  questions  given  orally  ;  I  to  3,  ditto  ;  6  to  9,  paper  of 
problems  in  Sidney  College  Hall. 

"Wednesday,  Jan.  I5th.  Questions  given  orally  8  to  9 
and  I  to  3,  with  paper  of  questions  on  Paley  and  Locke  (one 
question  only  in  each  was  answered). 

"Thursday,  Jan.  i6th.  We  went  in  at  9  and  I,  but  there 
seems  to  have  been  little  serious  examination. 

"  Friday,  Jan.  i/th.  On  this  day  the  brackets  or  classes  as 
resulting  from  the  examination  were  published,  ist  bracket 
Airy,  2nd  bracket  Jeffries,  3rd  bracket  Drinkwater,  Fisher, 
Foley,  Mason,  Myers. 


40  GEORGE   BIDDELL  AIRY. 

"  On  Saturday,  Jan.  i8th,  the  degrees  were  conferred  in  the 
usual  way.  It  had  been  arranged  that  my  brother  and  sister 
should  come  to  see  me  take  my  degree  of  B.A.,  and  I  had 
asked  Gibson  to  conduct  them  to  the  Senate  House  Gallery : 
but  Mr  Hawkes  (a  Trinity  Fellow)  found  them  and  stationed 
them  at  the  upper  end  of  the  Senate  House.  After  the 
preliminary  arrangements  of  papers  at  the  Vice-Chancellor's 
table,  I,  as  Senior  Wrangler,  was  led  up  first  to  receive  the 
degree,  and  rarely  has  the  Senate  House  rung  with  such 
applause  as  then  filled  it.  For  many  minutes,  after  I  was 
brought  in  front  of  the  Vice-Chancellor,  it  was  impossible  to 
proceed  with  the  ceremony  on  account  of  the  uproar.  I  gave 
notice  to  the  Smith's  Prize  Electors  of  my  intention  to  '  sit ' 
for  that  prize,  and  dined  at  Rothman's  rooms  with  Drink- 
water,  Buckle,  and  others.  On  Monday,  Jan.  2Oth,  I  was 
examined  by  Professor  Woodhouse,  for  Smith's  Prize,  from 
10  to  i.  I  think  that  the  only  competitor  was  Jeffries.  On 
Tuesday  I  was  examined  by  Prof.  Turton,  10  to  i,  and  on 
Wednesday  by  Prof.  Lax,  10  to  I.  On  Thursday,  Jan.  23rd, 
I  went  to  Bury  by  coach,  on  one  of  the  coldest  evenings  that 
I  ever  felt. 

"  Mr  Peacock  had  once  recommended  me  to  sit  for  the 
Chancellor's  medal  (Classical  Prize).  But  he  now  seemed  to 
be  cool  in  his  advice,  and  I  laid  aside  all  thought  of  it." 


It  seems  not  out  of  place  to  insert  here  a  copy  of  some 
"Cambridge  Reminiscences"  written  by  Airy,  which  will 
serve  to  explain  the  Acts  and  Opponencies  referred  to  in 
the  previous  narrative,  and  other  matters. 


THE  ACTS. 

The  examination  for  B.A.  degrees  was  preceded,  in  my 
time,  by  keeping  two  Acts,  in  the  Schools  under  the  Univer- 
sity Library:  the  second  of  them  in  the  October  term  imme- 


FROM   BIRTH   TO   B.A.   DEGREE.  41 

diately  before  the  examination ;  the  first  (I  think)  in  the 
October  term  of  the  preceding  year. 

These  Acts  were  reliques  of  the  Disputations  of  the 
Middle  Ages,  which  probably  held  a  very  important  place 
in  the  discipline  of  the  University.  (There  seems  to  be 
something  like  them  in  some  of  the  Continental  Universities.) 
The  presiding  authority  was  one  of  the  Moderators.  I  appre- 
hend that  the  word  "  Moderator "  signified  "  President,"  in 
which  sense  it  is  still  used  in  the  Kirk  of  Scotland  ;  and  that 
it  was  peculiarly  applied  to  the  Presidency  of  the  Disputa- 
tions, the  most  important  educational  arrangement  in  the 
University.  The  Moderator  sent  a  summons  to  the  "  Re- 
spondent" to  submit  three  subjects  for  argument,  and  to 
prepare  to  defend  them  on  a  given  day  :  he  also  named  three 
Opponents.  This  and  all  the  following  proceedings  were 
conducted  in  Latin.  For  my  Act  of  1822,  Nov.  6,  I  sub- 
mitted the  following  subjects : 

"  Recte  statuit  Newtonus  in  Principiis  suis  Mathematicis, 
libro  primo,  sectione  undecima." 

"  Recte  statuit  Woodius  de  Iride." 

"  Recte  statuit  Paleius  de  Obligationibus." 

The  Opponents  named  to  attack  these  assertions  were 
Hamilton  of  St  John's,  Rusby  of  St  Catharine's,  Field  of 
Trinity.  It  was  customary  for  the  Opponents  to  meet  at  tea 
at  the  rooms  of  the  Senior  Opponent,  in  order  to  discuss  and 
arrange  their  arguments ;  the  Respondent  was  also  invited, 
but  he  was  warned  that  he  must  depart  as  soon  as  tea  would 
be  finished :  then  the  three  Opponents  proceeded  with  their 
occupation.  As  I  have  acted  in  both  capacities,  I  am  able  to 
say  that  the  matter  was  transacted  in  an  earnest  and  business- 
like way.  Indeed  in  the  time  preceding  my  own  (I  know  not 
whether  in  my  own  time)  the  assistance  of  a  private  tutor  was 
frequently  engaged,  and  I  remember  hearing  a  senior  M.A. 
remark  that  my  College  Tutor  (James  D.  Hustler)  was  the 
best  crammer  for  an  Act  in  the  University. 

At  the  appointed  time,  the  parties  met  in  the  Schools : 


42  GEORGE   BIDDELL  AIRY. 

the  Respondent  first  read  a  Latin  Thesis  on  any  subject  (I 
think  I  took  some  metaphysical  subject),  but  nobody  paid 
any  attention  to  it:  then  the  Respondent  read  his  first  Dogma, 
and  the  first  Opponent  produced  an  argument  against  it,  in 
Latin.  After  this  there  were  repeated  replies  and  rejoinders, 
all  in  viva  voce  Latin,  the  Moderator  sometimes  interposing 
a  remark  in  Latin.  When  he  considered  that  one  argument 
was  disposed  of,  he  called  for  another  by  the  words  "  Probes 
aliter."  The  arguments  were  sometimes  shaped  with  con- 
siderable ingenuity,  and  required  a  clear  head  in  the  Respon- 
dent. When  all  was  finished,  the  Moderator  made  a  compli- 
mentary remark  to  the  Respondent  and  one  to  the  first 
Opponent  (I  forget  whether  to  the  second  and  third).  In  my 
Respondency  of  1822,  November  6,  the  compliment  was, 
"  Quaestiones  tuas  summo  ingenio  et  acumine  defendisti,  et  in 
rebus  mathematicis  scientiam  plane  mirabilem  ostendisti.' 
In  an  Opponency  (I  forget  when)  the  compliment  was, 
"  Magno  ingenio  argumenta  tua  et  construxisti  et  defen- 
disti." 

The  Acts  of  the  high  men  excited  much  interest  among 
the  students.  At  my  Acts  the  room  was  crowded  with 
undergraduates. 

I  imagine  that,  at  a  time  somewhat  distant,  the  mainte- 
nance of  the  Acts  was  the  only  regulation  by  which  the 
University  acted  on  the  studies  of  the  place.  When  the 
Acts  had  been  properly  kept,  license  was  given  to  the  Father 
of  the  College  to  present  the  undergraduate  to  the  Vice- 
Chancellor,  who  then  solemnly  admitted  him  "ad  respon- 
dendum  Quaestioni."  There  is  no  appearance  of  collective 
examination  before  this  presentation :  what  the  "  Quaestio " 
might  be,  I  do  not  know.  Still  the  undergraduate  was  not 
B.A.  The  Quaestio  however  was  finished  and  approved 
before  the  day  of  a  certain  Congregation,  and  then  the  under- 
graduate was  declared  to  be  "actualiter  in  artibus  Bacca- 
laureum." 

Probably  these  regulations  were  found  to  be  insufficient 


FROM   BIRTH   TO   B.A.   DEGREE.  43 

for  the  control  of  education,  and  the  January  examination 
was  instituted.  I  conjecture  this  to  have  been  at  or  shortly 
before  the  date  of  the  earliest  Triposes  recorded  in  the 
Cambridge  Calendar,  1748. 

The  increasing  importance  of  the  January  examination 
naturally  diminished  the  value  of  the  Acts  in  the  eyes  of  the 
undergraduates ;  and,  a  few  years  after  my  M.A.  degree,  it 
was  found  that  the  Opponents  met,  not  for  the  purpose  of 
concealing  their  arguments  from  the  Respondent,  but  for  the 
purpose  of  revealing  them  to  him.  This  led  to  the  entire 
suppression  of  the  system.  The  most  active  man  in  this 
suppression  was  Mr  Whewell :  its  date  must  have  been  near 
to  1830. 

The  shape  in  which  the  arguments  were  delivered  by  an 
Opponent,  reading  from  a  written  paper,  was,  "  Si  (quoting 
something  from  the  Respondent's  challenge),  &c.,  &c.  Cadit 
Quaestio ;  Sed  (citing  something  else  bearing  on  the  subject 
of  discussion),  Valet  Consequentia ;  Ergo  (combining  these 
to  prove  some  inaccuracy  in  the  Respondent's  challenge), 
Valent  Consequentia  et  Argumentum."  Nobody  pretended 
to  understand  these  mystical  terminations. 

Apparently  the  original  idea  was  that  several  Acts  should 
be  kept  by  each  undergraduate  ;  for,  to  keep  up  the  number 
(as  it  seemed),  each  student  had  to  gabble  through  a  ridicu- 
lous form  "  Si  quaestiones  tuae  falsae  sint,  Cadit  Quaestio : — sed 
quaestiones  tuae  falsae  sunt,  Ergo  valent  Consequentia  et  Argu- 
mentum." I  have  forgotten  time  and  place  when  this  was 
uttered. 

THE  SENATE-HOUSE  EXAMINATION. 

The  Questionists,  as  the  undergraduates  preparing  for 
B.A.  were  called  in  the  October  term,  were  considered  as  a 
separate  body;  collected  at  a  separate  table  in  Hall,  attending 
no  lectures,  but  invited  to  attend  a  system  of  trial  examina- 
tions conducted  by  one  of  the  Tutors  or  Assistant-Tutors. 


44  GEORGE   BIDDELL  AIRY. 

From  the  Acts,  from  the  annual  College  examinations, 
and  (I  suppose)  from  enquiries'  in  the  separate  Colleges,  the 
Moderators  acquired  a  general  idea  of  the  relative  merits  of 
the  candidates  for  honours.  Guided  by  this,  the  candidates 
were  divided  into  six  classes.  The  Moderators  and  Assistant 
Examiners  were  provided  each  with  a  set  of  questions  in 
manuscript  (no  printed  papers  were  used  for  Honours  in  the 
Senate  House  ;  in  regard  to  the  ol  TroXXol  I  cannot  say).  On 
the  Monday  on  which  the  examination  began,  the  Father  of 
the  College  received  all  the  Questionists  (I  believe),  at  any 
rate  all  the  candidates  for  honours,  at  breakfast  in  the  Combi- 
nation Room  at  8  o'clock,  and  marched  them  to  the  Senate 
House.  My  place  with  other  honour-men  was  in  the  East 
Gallery.  There  one  Examiner  took  charge  of  the  1st  and 
2nd  classes  united,  another  Examiner  took  the  3rd  and  4th 
classes  united,  and  a  third  took  the  5th  and  6th  united.  On 
Tuesday,  one  Examiner  took  the  ist  class  alone,  a  second 
took  the  2nd  and  3rd  classes  united,  a  third  took  the  4th  and 
5th  classes  united,  and  a  fourth  took  the  6th  class  alone.  On 
Wednesday,  Thursday,  and  Friday  the  changes  were  similar. 
And,  in  all,  the  questioning  was  thus  conducted.  The 
Examiner  read  from  his  manuscript  the  first  question. 
Those  who  could  answer  it  proceeded  to  write  out  their 
answers,  and  as  soon  as  one  had  finished  he  gave  the  word 
"Done";  then  the  Examiner  read  out  his  second  question, 
repeating  it  when  necessary  for  the  understanding  by  those 
who  took  it  up  more  lately.  And  so  on.  I  think  that  the 
same  process  was  repeated  in  the  afternoon  ;  but  I  do  not 
remember  precisely.  In  this  manner  the  Examination  was 
conducted  through  five  days  (Monday  to  Friday)  with  no 
interruption  except  on  Friday  afternoon.  It  was  principally, 
perhaps  entirely,  bookwork. 

But  on  two  evenings  there  were  printed  papers  of  prob- 
lems: and  the  examination  in  these  was  conducted  just  as 
in  the  printed  papers  of  the  present  day :  but  in  the  private 
College  Rooms  of  the  Moderators.  And  there,  wine  and 


FROM    BIRTH   TO   B.A.   DEGREE.  45 

other  refreshments  were  offered  to  the  Examinees.  How 
this  singular  custom  began,  I  know  not. 

The  order  of  merit  was  worked  out  on  Friday  afternoon 
and  evening,  and  was  in  some  measure  known  through  the 
University  late  in  the  evening.  I  remember  Mr  Peacock 
coming  to  a  party  of  Examinees  and  giving  information  on 
several  places.  I  do  not  remember  his  mentioning  mine 
(though  undoubtedly  he  did)  but  I  distinctly  remember  his 
giving  the  Wooden  Spoon.  On  the  Saturday  morning  at 
8  o'clock  the  manuscript  list  was  nailed  to  the  door  of  the 
Senate-House.  The  form  of  further  proceedings  in  the  pre- 
sentation for  degree  (ad  respondendum  quaestioni)  I  imagine 
has  not  been  much  altered.  The  kneeling  before  the  Vice- 
Chancellor  and  placing  hands  in  the  Vice-Chancellor's  hands 
were  those  of  the  old  form  of  doing  homage. 

The  form  of  examination  which  I  have  described  was 
complicated  and  perhaps  troublesome,  but  I  believe  that  it 
was  very  efficient,  possibly  more  so  than  the  modern  form 
(established  I  suppose  at  the  same  time  as  the  abolition  of 
the  Acts).  The  proportion  of  questions  now  answered  to  the 
whole  number  set  is  ridiculously  small,  and  no  accurate  idea 
of  relative  merit  can  be  formed  from  them. 

THE  COLLEGE  HALL. 

When  I  went  up  in  1819,  and  for  several  years  later,  the 
dinner  was  at  J  past  3.  There  was  no  supplementary  dinner 
for  special  demands.  Boat-clubs  I  think  were  not  invented, 
even  in  a  plain  social  way,  till  about  1824  or  1825;  and  not 
in  connection  with  the  College  till  some  years  later.  Some 
of  the  senior  Fellows  spoke  of  the  time  when  dinner  was  at  2, 
and  regretted  the  change. 

There  was  supper  in  Hall  at  9  o'clock  :  I  have  known  it 
to  be  attended  by  a  few  undergraduates  when  tired  by  ex- 
aminations or  by  evening  walks;  and  there  were  always  some 
seniors  at  the  upper  table:  I  have  occasionally  joined  them, 


46  GEORGE  BIDDELL  AIRY. 


and  have  had  some  very  interesting  conversations.  The 
supper  was  cold,  but  hot  additions  were  made  when  re- 
quired. 

One  little  arrangement  amused  me,  as  shewing  the 
ecclesiastical  character  of  the  College.  The  Fasts  of  the 
Church  were  to  be  strictly  kept,  and  there  was  to  be  no 
dinner  in  Hall.  It  was  thus  arranged.  The  evening  chapel 
service,  which  was  usually  at  5^  (I  think),  was  held  at  3;  and 
at  4  the  ordinary  full  meal  was  served  in  Hall,  but  as  it 
followed  the  chapel  attendance  it  was  held  to  be  supper;  and 
there  was  no  subsequent  meal. 

There  were  no  chairs  whatever  in  Hall,  except  the  single 
chair  of  the  vice-master  at  the  head  of  the  table  on  the  dais 
and  that  of  the  senior  dean  at  the  table  next  the  East  wall. 
All  others  sat  on  benches.  And  I  have  heard  allusions  to  a 
ludicrous  difficulty  which  occurred  when  some  princesses  (of 
the  Royal  Family)  dined  in  the  Hall,  and  it  was  a  great 
puzzle  how  to  get  them  to  the  right  side  of  the  benches. 

The  Sizars  dined  after  all  the  rest;  their  dinner  usually 
began  soon  after  4.  For  the  non-foundationists  a  separate 
dinner  was  provided,  as  for  pensioners.  But  for  the  founda- 
tionists,  the  remains  of  the  Fellows'  dinner  were  brought 
down ;  and  I  think  that  this  provision  was  generally  preferred 
to  the  other. 

The  dishes  at  all  the  tables  of  undergraduates  were  of 
pewter,  till  a  certain  day  when  they  were  changed  for  porce- 
lain. I  cannot  remember  whether  this  was  at  the  time  when 
they  became  Questionists  (in  the  October  Term),  or  at  the 
time  when  they  were  declared  "actualiter  esse  in  artibus 
Baccalaureos  "  (in  the  Lent  Term). 

Up  to  the  Questionist  time  the  undergraduate  Scholars 
had  no  mixture  whatever;  they  were  the  only  pure  table  in 
the  Hall :  and  I  looked  on  this  as  a  matter  very  valuable  for 
the  ultimate  state  of  the  College  society.  But  in  the  October 
term,  those  who  were  to  proceed  to  B.A.  were  drafted  into 
the  mixed  body  of  Questionists  :  and  they  greatly  disliked 


FROM   BIRTH   TO   B.A.   DEGREE.  47 

the  change.  They  continued  so  till  the  Lent  Term,  when 
they,  were  formally  invited  by  the  Bachelor  Scholars  to  join 
the  upper  table. 


MATHEMATICAL  SUBJECTS  OF  STUDY  AND  EXAMINATION. 

In  the  October  Term  1819,  the  only  books  on  Pure 
Mathematics  were: — Euclid  generally,  Algebra  by  Dr  Wood 
(formerly  Tutor,  but  in  1819  Master,  of  St  John's  College), 
Vince's  Fluxions  and  Dealtry's  Fluxions,  Woodhouse's  and 
other  Trigonometries.  Not  a  whisper  passed  through  the 
University  generally  on  the  subject  of  Differential  Calculus ; 
although  some  papers  (subsequently  much  valued)  on  that 
subject  had  been  written  by  Mr  Woodhouse,  fellow  of  Caius 
College ;  but  their  style  was  repulsive,  and  they  never  took 
hold  of  the  University.  Whewell's  Mechanics  (1819)  contains 
a  few  and  easy  applications  of  the  Differential  Calculus. 
The  books  on  applied  Mathematics  were  Wood's  Mechanics, 
Whewell's  Mechanics,  Wood's  Optics,  Vince's  Hydrostatics, 
Vince's  Astronomy,  Woodhouse's  Plane  Astronomy  (perhaps 
rather  later),  The  First  Book  of  Newton's  Principia:  I  do  not 
remember  any  others.  These  works  were  undoubtedly  able; 
and  for  the  great  proportion  of  University  students  going 
into  active  life,  I  do  not  conceal  my  opinion  that  books  con- 
structed on  the  principles  of  those  which  I  have  cited  were 
more  useful  than  those  exclusively  founded  on  the  more 
modern  system.  For  those  students  who  aimed  at  the 
mastery  of  results  more  difficult  and  (in  the  intellectual  sense) 
more  important,  the  older  books  were  quite  insufficient. 
More  aspiring  students  read,  and  generally  with  much  care, 
several  parts  of  Newton's  Principia,  Book  I.,  and  also  Book  III. 
(perhaps  the  noblest  example  of  geometrical  form  of  cosmical 
theory  that  the  world  has  seen).  I  remember  some  questions 
from  Book  III.  proposed  in  the  Senate-House  Examination 
1823. 


48  GEORGE  BIDDELL  AIRY. 

In  the  October  term  1819,  I  went  up  to  the  University. 
The  works  of  Wood  and  Vince*  which  I  have  mentioned,  still 
occupied  the  lecture-rooms.  But  a  great  change  was  in 
preparation  for  the  University  Course  of  Mathematics. 
During  the  great  Continental  war,  the  intercourse  between 
men  of  science  in  England  and  in  France  had  been  most 
insignificant.  But  in  the  autumn  of  1819,  three  members  of 
the  Senate  (John  Herschel,  George  Peacock,  and  Charles 
Babbage)  had  entered  into  the  mathematical  society  of  Paris, 
and  brought  away  some  of  the  works  on  Pure  Mathematics 
(especially  those  of  Lacroix)  and  on  Mechanics  (principally 
Poisson's).  In  1820  they  made  a  translation  of  Lacroix's 
Differential  Calculus ;  and  they  prepared  a  volume  of  Ex- 
amples of  the  Differential  and  Integral  Calculus.  These 
were  extensively  studied :  but  the  form  of  the  College  Ex- 
aminations or  the  University  Examinations  was  not,  I  think, 
influenced  by  them  in  the  winter  1820 — 1821  or  the  two 
following  terms.  But  in  the  winter  1821 — 1822  Peacock  was 
one  of  the  Moderators ;  and  in  the  Senate-House  Examina- 
tion, January  1822,  he  boldly  proposed  a  Paper  of  important 
questions  entirely  in  the  Differential  Calculus.  This  was 
considered  as  establishing  the  new  system  in  the  University. 
In  January  1823,  I  think  the  two  systems  were  mingled. 
Though  I  was  myself  subject  to  that  examination,  I  grieve  to 
say  that  I  have  forgotten  much  of  the  details,  except  that  I 
well  remember  that  some  of  the  questions  referred  to  Newton, 
Book  III.  on  the  Lunar  Theory.  To  these  I  have  already 
alluded. 

No  other  work  occurs  to  me  as  worthy  of  mention,  except 
Woodhouse's  Lunar  Theory,  entirely  founded  on  the  Dif- 
ferential Calculus.  The  style  of  this  book  was  not  attractive, 
and  it  was  very  little  read. 


CHAPTER    III. 

AT  TRINITY  COLLEGE,  CAMBRIDGE,  FROM  HIS  TAKING 
HIS  B.A.  DEGREE  TO  HIS  TAKING  CHARGE  OF  THE 
CAMBRIDGE  OBSERVATORY  AS  PLUMIAN  PROFESSOR. 

FROM  JANUARY  ISTH,  1823,  TO  MARCH  ISTH,  1828. 

"ON  Jan.  3<Dth,  1823,  I  returned  to  Cambridge.  I  had 
already  heard  that  I  had  gained  the  1st  Smith's  Prize,  and 
one  of  the  first  notifications  to  me  on  my  return  was  that  the 
Walker's  good-conduct  prize  of  £10  was  awarded  to  me. 

"  I  remember  that  my  return  was  not  very  pleasant,  for  our 
table  in  hall  was  half  occupied  by  a  set  of  irregular  men  who 
had  lost  terms  and  were  obliged  to  reside  somewhat  longer  in 
order  to  receive  the  B.A.  degree.  But  at  the  time  of  my 
completing  the  B.A.  degree  (which  is  not  till  some  weeks 
after  the  examination  and  admission)  I  with  the  other  com- 
plete bachelors  was  duly  invited  to  the  table  of  the  B.A. 
scholars,  and  that  annoyance  ended. 

"The  liberation  from  undergraduate  study  left  me  at  liberty 
generally  to  pursue  my  own  course  (except  so  far  as  it  was 
influenced  by  the  preparation  for  fellowship  examination), 
and  also  left  me  at  liberty  to  earn  more  money,  in  the  way 
usual  with  the  graduates,  by  taking  undergraduate  pupils.  Mr 
Peacock  recommended  me  to  take  only  four,  which  occupied 
me  four  hours  every  day,  and  for  each  of  them  I  received 
20  guineas  each  term.  My  first  pupils,  for  the  Lent  and 
Easter  terms,  were  Williamson  (afterwards  Head  Master  of 
Westminster  School),  James  Parker  (afterwards  Q.C.  and 
A.  B.  4 


50  GEORGE   BIDDELL  AIRY. 

Vice-Chancellor),  Bissett,  and  Clinton  of  Caius.  To  all  these 
I  had  been  engaged  before  taking  my  B.A.  degree. 

"  I  kept  up  classical  subjects.  I  have  a  set  of  notes  on  the 
nXouro?  and  Ne<£e\a*  of  Aristophanes,  finished  on  Mar.  1 5th, 
1823,  and  I  began  my  daily  writing  of  Latin  as  usual  on 
Feb.  8th.  In  mathematics  I  worked  very  hard  at  Lunar  and 
Planetary  Theories.  I  have  two  MS.  books  of  Lunar  Theory 
to  the  5th  order  of  small  quantities,  which  however  answered 
no  purpose  except  that  of  making  me  perfectly  familiar  with 
that  subject.  I  worked  well,  upon  my  quires,  the  figure  of 
Saturn  supposed  homogeneous  as  affected  by  the  attraction 
of  his  ring,  and  the  figure  of  the  Earth  as  heterogeneous,  and 
the  Calculus  of  Variations.  I  think  it  was  now  that  I  wrote 
a  MS.  on  constrained  motion. 

"On  Mar.  i;th,  1823,  I  was  elected  Fellow  of  the  Cam- 
bridge Philosophical  Society.  On  May  Qth  a  cast  of  my  head 
was  taken  for  Dr  Elliotson,  an  active  phrenologist,  by  Deville, 
a  tradesman  in  the  Strand. 

"  I  had  long  thought  that  I  should  like  to  visit  Scotland, 
and  on  my  once  saying  so  to  my  mother,  she  (who  had  a 
most  kindly  recollection  of  Alnwick)  said  in  a  few  words  that 
she  thought  I  could  not  do  better.  I  had  therefore  for  some 
time  past  fully  determined  that  as  soon  as  I  had  sufficient 
spare  time  and  money  enough  I  would  go  to  Scotland.  The 
interval  between  the  end  of  Easter  Term  and  the  usual 
beginning  with  pupils  in  the  Long  Vacation  offered  sufficient 
time,  and  I  had  now  earned  a  little  money,  and  I  therefore 
determined  to  go,  and  invited  my  sister  to  accompany  me. 
I  had  no  private  introductions,  except  one  from  James  Parker 
to  Mr  Reach,  a  writer  of  Inverness  :  some  which  Drinkwater 
sent  being  too  late.  On  May  2Oth  we  went  by  coach  to 
Stamford  ;  thence  by  Pontefract  and  Oulton  to  York,  where 
I  saw  the  Cathedral,  which  then  disappointed  me,  but  I  suppose 
that  we  were  tired  with  the  night  journey.  Then  by  Newcastle 
to  Alnwick,  where  we  stopped  for  the  day  to  see  my  birth- 
place. On  May  24th  to  Edinburgh.  On  this  journey  I 


FROM   B.A.    DEGREE  TO   PLUMIAN    PROFESSORSHIP.       51 

remember  well  the  stone  walls  between  the  fields,  the  place 
(in  Yorkshire)  where  for  the  first  time  in  my  life  I  saw  rock, 
the  Hambleton,  Kyloe,  Cheviot  and  Pentland  Hills,  Arthur's 
Seat,  but  still  more  strikingly  the  revolving  Inch  Keith  Light. 
At  Edinburgh  I  hired  a  horse  and  gig  for  our  journey  in 
Scotland,  and  we  drove  by  Queensferry  to  Kinross  (where  for 
the  first  time  in  my  life  I  saw  clouds  on  the  hills,  viz.  on  the 
Lomond  Hills),  and  so  to  Perth.  Thence  by  Dunkeld  and 
Killicrankie  to  Blair  Athol  (the  dreariness  of  the  Drumochter 
Pass  made  a  strong  impression  on  me),  and  by  Aviemore 
(where  I  saw  snow  on  the  mountains)  to  Inverness.  Here  we 
received  much  kindness  and  attention  from  Mr  Reach,  and 
after  visiting  the  Falls  of  Foyers  and  other  sights  we  went  to 
Fort  Augustus  and  Fort  William.  We  ascended  Ben  Nevis, 
on  which  there  was  a  great  deal  of  snow,  and  visited  the 
vitrified  fort  in  Glen  Nevis.  Then  by  Inverary  to  Tarbet, 
and  ascended  Ben  Lomond,  from  whence  we  had  a  magnifi- 
cent view.  We  then  passed  by  Loch  Achray  to  Glasgow, 
where  we  found  James  Parker's  brother  (his  father,  of  the 
house  of  Macinroy  and  Parker,  being  a  wealthy  merchant  of 
Glasgow).  On  June  I5th  to  Mr  Parker's  house  at  Blochairn, 
near  Glasgow  (on  this  day  I  heard  Dr  Chalmers  preach),  and 
on  the  i /th  went  with  the  family  by  steamer  (the  first  that  I 
had  seen)  to  Fairly,  near  Largs.  I  returned  the  gig  to  Edin- 
burgh, visited  Arran  and  Bute,  and  we  then  went  by  coach  to 
Carlisle,  and  by  Penrith  to  Keswick  (by  the  old  road  :  never 
shall  I  forget  the  beauty  of  the  approach  to  Keswick).  After 
visiting  Ambleside  and  Kendal  we  returned  to  Cambridge  by 
way  of  Leeds,  and  posted  to  Bury  on  the  28th  June.  The 
expense  of  this  expedition  was  about  £81.  It  opened  a  com- 
pletely new  world  to  me. 

"  I  had  little  time  to  rest  at  Bury.  In  the  preceding  term 
Drinkwater,  Buckle,  and  myself,  had  engaged  to  go  some- 
where into  the  country  with  pupils  during  the  Long  Vacation 
(as  was  customary  with  Cambridge  men).  Buckle  however 
changed  his  mind.  Drinkwater  went  to  look  for  a  place, 

4—2 


52  GEORGE   BIDDELL  AIRY. 

fixed  on  Swansea,  and  engaged  a  house  (called  the  Cambrian 
Hotel,  kept  by  a  Captain  Jenkins).  On  the  morning  of 
July  2nd  I  left  Bury  for  London  and  by  mail  coach  to 
Bristol.  On  the  morning  of  July  3rd  by  steamer  to  Swansea, 
and  arrived  late  at  night.  I  had  then  five  pupils:  Parker, 
Harman  Lewis  (afterwards  Professor  in  King's  College,  Lon- 
don), Pierce  Morton,  Gibson,  and  Guest  of  Caius  (afterwards 
Master  of  the  College).  Drinkwater  had  four,  viz.  two 
Malkins  (from  Bury),  Elphinstone  (afterwards  M.P.),  and 
Parish  (son  of  Professor  Parish).  We  lived  a  hard-working 
strange  life.  My  pupils  began  with  me  at  six  in  the  morning : 
I  was  myself  reading  busily.  We  lived  completely  enfamille, 
with  two  men-servants  besides  the  house  establishment.  One 
of  our  first  acts  was  to  order  a  four-oared  boat  to  be  built, 
fitted  with  a  lug-sail :  she  was  called  the  Granta  of  Swansea. 
In  the  meantime  we  made  sea  excursions  with  boats  borrowed 
from  ships  in  the  port.  On  July  23rd,  with  a  borrowed  boat, 
we  went  out  when  the  sea  was  high,  but  soon  found  our  boat 
unmanageable,  and  at  last  got  into  a  place  where  the  sea  was 
breaking  heavily  over  a  shoal,  and  the  two  of  the  crew  who 
were  nearest  to  me  (A.  Malkin  and  Lewis),  one  on  each  side, 
were  carried  out :  they  were  good  swimmers  and  we  recovered 
them,  though  with  some  trouble :  the  breaker  had  passed 
quite  over  my  head  :  we  gained  the  shore  and  the  boat  was 
taken  home  by  land.  When  our  own  boat  was  finished,  we 
had  some  most  picturesque  adventures  at  the  Mumbles, 
Aberavon,  Caswell  Bay,  Ilfracombe,  and  Tenby.  From  all 
this  I  learnt  navigation  pretty  well.  The  mixture  of  hard 
study  and  open-air  exertion  seemed  to  affect  the  health  of 
several  of  us  (I  was  one) :  we  were  covered  with  painful  boils. 
"  My  Latin-writing  began  again  on  July  25th  :  I  have  notes 
on  Demosthenes,  Lucretius,  and  Greek  History.  In  mathe- 
matics I  find  Chances,  Figure  of  the  Earth  with  variable 
density,  Differential  Equations,  Partial  Differentials,  sketch 
for  an  instrument  for  shewing  refraction,  and  Optical  instru- 
ments with  effects  of  chromatic  aberration.  In  August  there 


FROM   B.A.   DEGREE   TO   PLUMIAN   PROFESSORSHIP.        53 

occurred  an  absurd  quarrel  between  the  Fellows  of  Trinity 
and  the  undergraduates,  on  the  occasion  of  commencing  the 
building  of  King's  Court,  when  the  undergraduates  were  not 
invited  to  wine,  and  absented  themselves  from  the  hall. 

"There  were  vacant  this  year  (1823)  five  fellowships  in 
Trinity  College.  In  general,  the  B.A.'s  of  the  first  year  are 
not  allowed  to  sit  for  fellowships :  but  this  year  it  was 
thought  so  probable  that  permission  would  be  given,  that  on 
Sept.  2nd  Mr  Higman,  then  appointed  as  Tutor  to  a  third 
'  side '  of  the  College,  wrote  to  me  to  engage  me  as  Assistant 
Mathematical  Tutor  in  the  event  of  my  being  elected  a 
Fellow  on  Oct.  ist,  and  I  provisionally  engaged  myself. 
About  the  same  time  I  had  written  to  Mr  Peacock,  who 
recommended  me  to  sit,  and  to  Mr  Whewell,  who  after  con- 
sultation with  the  Master  (Dr  Wordsworth),  discouraged  it. 
As  there  was  no  absolute  prohibition,  I  left  Swansea  on  Sept. 
nth  (before  my  engagement  to  my  pupils  was  quite  finished) 
and  returned  to  Cambridge  by  Gloucester,  Oxford,  and 
London.  I  gave  in  my  name  at  the  butteries  as  candidate  for 
fellowship,  but  was  informed  in  a  day  or  two  that  I  should 
not  be  allowed  to  sit.  On  Sept.  ipth  I  walked  to  Bury. 

"  I  walked  back  to  Cambridge  on  Oct.  i/th,  1823.  During 
this  October  term  I  had  four  pupils  :  Neate,  Cankrein,  Turner 
(afterwards  2nd  wrangler  and  Treasurer  of  Guy's  Hospital), 
and  William  Hervey  (son  of  the  Marquis  of  Bristol).  In  the 
Lent  term  I  had  four  (Neate,  Cankrein,  Turner,  Clinton). 
In  the  Easter  term  I  had  three  (Neate,  Cankrein,  Turner). 

"  My  daily  writing  of  Latin  commenced  on  Oct.  27th.  In 
November  I  began  re-reading  Sophocles  with  my  usual  care. 
In  mathematics  I  find  investigations  of  Motion  in  a  resisting 
medium,  Form  of  Saturn,  Draft  of  a  Paper  about  an  instru- 
ment for  exhibiting  the  fundamental  law  of  refraction  (read 
at  the  Philosophical  Society  by  Mr  Peacock  on  Nov.  loth, 
1823),  Optics,  Solid  Geometry,  Figure  of  the  Earth  with 
variable  density,  and  much  about  attractions.  I  also  in  this 
term  wrote  a  MS.  on  the  Calculus  of  Variations,  and  one  on 


54  GEORGE  BIDDELL  AIRY. 

Wood's  Algebra,  2nd  and  4th  parts.  I  have  also  notes  of  the 
temperature  of  mines  in  Cornwall,  something  on  the  light  of 
oil-gas,  and  reminiscences  of  Swansea  in  a  view  of  Oswick 
Bay.  In  November  I  attended  Professor  Sedgwick's  geo- 
logical lectures. 

"At  some  time  in  this  term  I  had  a  letter  from  Mr  South 
(to  whom  I  suppose  I  had  written)  regarding  the  difficulty  of 
my  telescope  :  he  was  intimately  acquainted  with  Tulley,  and 
I  suppose  that  thus  the  matter  had  become  more  fully  known 
to  him.  He  then  enquired  if  I  could  visit  him  in  the  winter 
vacation.  I  accordingly  went  from  Bury,  and  was  received 
by  him  at  his  house  in  Blackman  Street  for  a  week  or  more 
with  great  kindness.  He  introduced  me  to  Sir  Humphrey 
Davy  and  many  other  London  savans,  and  shewed  me  many 
London  sights  and  the  Greenwich  Observatory.  I  also  had 
a  little  practice  with  his  own  instruments.  He  was  then  on 
intimate  terms  with  Mr  Herschel  (afterwards  Sir  John  Her- 
schel), then  living  in  London,  who  came  occasionally  to 
observe  double  stars.  This  was  the  first  time  that  I  saw 
practical  astronomy.  It  seems  that  I  borrowed  his  mountain 
barometer.  In  the  Lent  term  I  wrote  to  him  regarding  the 
deduction  of  the  parallax  of  Mars,  from  a  comparison  of  the 
relative  positions  of  Mars  and  46  Leonis,  as  observed  by  him 
and  by  Rumker  at  Paramatta.  My  working  is  on  loose 
papers.  I  see  that  I  have  worked  out  perfectly  the  interpo- 
lations, the  effects  of  uncertainty  of  longitude,  &c.,  but  I  do 
not  see  whether  I  have  a  final  result. 

"  In  Jan.  1824,  at  Playford,  I  was  working  on  the  effects  of 
separating  the  two  lenses  of  an  object-glass,  and  on  the  kind 
of  eye-piece  which  would  be  necessary :  also  on  spherical 
aberrations  and  Saturn's  figure.  On  my  quires  at  Cambridge 
I  was  working  on  the  effects  of  separating  the  object-glass 
lenses,  with  the  view  of  correcting  the  secondary  spectrum  :  and 
on  Jan.  3ist  I  received  some  numbers  (indices  of  refraction) 
from  Mr  Herschel,  and  reference  to  Fraunhofer's  numbers. 

"  About  this  time  it  was  contemplated  to  add  to  the  Royal 


FROM   B.A.   DEGREE  TO   PLUMIAN   PROFESSORSHIP.       55 

Observatory  of  Greenwich  two  assistants  of  superior  educa- 
tion. Whether  this  scheme  was  entertained  by  the  Admiralty, 
the  Board  of  Longitude,  or  the  Royal  Society,  I  do  not  know. 
Somehow  (I  think  through  Mr  Peacock)  a  message  from  Mr 
Herschel  was  conveyed  to  me,  acquainting  me  of  this,  and 
suggesting  that  I  should  be  an  excellent  person  for  the  prin- 
cipal place.  To  procure  information,  I  went  to  London  on 
Saturday,  Feb.  7th,  sleeping  at  Mr  South's,  to  be  present  at 
one  of  Sir  Humphrey  Davy's  Saturday  evening  soirees  (they 
were  then  held  every  Saturday),  and  to  enquire  of  Sir  H. 
Davy  and  Dr  Young.  When  I  found  that  succession  to  the 
post  of  Astronomer  Royal  was  not  considered  as  distinctly  a 
consequence  of  it,  I  took  it  coolly,  and  returned  the  next 
night.  The  whole  proposal  came  to  nothing. 

"  At  this  time  I  was  engaged  upon  differential  equations, 
mountain  barometer  problem  and  determination  of  the  height 
of  the  Gogmagogs  and  several  other  points,  investigations 
connected  with  Laplace's  calculus,  spherical  aberration  in 
different  planes,  geology  (especially  regarding  Derbyshire, 
which  I  proposed  to  visit),  and  much  of  optics.  I  wrote  a 
draft  of  my  Paper  on  the  figure  of  Saturn,  and  on  Mar.  I5th, 
1824,  it  was  read  at  the  Philosophical  Society  under  the  title 
of  '  On  the  figure  assumed  by  a  fluid  homogeneous  mass, 
whose  particles  are  acted  on  by  their  mutual  attraction,  and 
by  small  extraneous  forces,'  and  is  printed  in  their  Memoirs. 
I  also  wrote  a  draft  of  my  Paper  on  Achromatic  Eye-pieces, 
and  on  May  i^th,  1824,  it  was  read  at  the  Philosophical 
Society  under  the  title  of  'On  the  Principles  and  Construc- 
tion of  the  Achromatic  Eye-pieces  of  Telescopes,  and  on  the 
Achromatism  of  Microscopes,'  including  also  the  effects  of 
separating  the  lenses  of  the  object-glass.  It  is  printed  in 
their  Memoirs. 

"Amongst  miscellaneous  matters  I  find  that  on  Mar.  22nd 
of  this  year  I  began  regularly  making  extracts  from  the 
books  of  the  Book  Society,  a  practice  which  I  continued  to 
March  1826.  On  Mar.  27th,  a  very  rainy  day,  I  walked  to 


56  GEORGE  BIDDELL  AIRY. 

Bury  to  attend  the  funeral  of  my  uncle  William  Biddell,  near 
Diss,  and  on  Mar.  3Oth  I  walked  back  in  rain  and  snow.  On 
Feb.  24th  I  dined  with  Cubitt  in  Cambridge.  On  May  2ist 
I  gave  a  certificate  to  Rogers  (the  assistant  in  Crosse's  school, 
and  my  instructor  in  mathematics),  which  my  mother  ampli- 
fied much,  and  which  I  believe  procured  his  election  as 
master  of  Walsall  School.  On  June  23rd  I  went  to  Bury. 
The  speeches  at  Bury  School,  which  I  wished  to  attend,  took 
place  next  day." 

At  this  point  of  his  Autobiography  the  writer  continues, 
"  Now  came  one  of  the  most  important  occurrences  in  my 
life."  The  important  event  in  question  was  his  acquaintance 
with  Richarda  Smith,  the  lady  who  afterwards  became  his 
wife.  The  courtship  was  a  long  one,  and  in  the  Auto- 
biography there  are  various  passages  relating  to  it,  all  written 
in  the  most  natural  and  unaffected  manner,  but  of  somewhat 
too  private  a  nature  for  publication.  It  will  therefore  be 
convenient  to  digress  from  the  straight  path  of  the  narrative 
in  order  to  insert  a  short  memoir  of  the  lady  who  was  destined 
to  influence  his  life  and  happiness  in  a  most  important  degree. 

Richarda  Smith  was  the  eldest  daughter  of  the  Rev. 
Richard  Smith,  who  had  been  a  Fellow  of  Trinity  College, 
Cambridge,  but  was  at  this  time  Private  Chaplain  to  the 
Duke  of  Devonshire,  and  held  the  small  living  of  Edensor, 
near  Chatsworth,  in  Derbyshire.  He  had  a  family  of  two 
sons  and  seven  daughters,  whom  he  had  brought  up  and 
educated  very  carefully.  Several  of  his  daughters  were 
remarkable  both  for  their  beauty  and  accomplishments. 
Richarda  Smith  was  now  in  her  2Oth  year,  and  the  writer 
of  the  Autobiography  records  that  "at  Matlock  we  received 
great  attention  from  Mr  Chenery :  in  speaking  of  Mr  Smith 
I  remember  his  saying  that  Mr  Smith  had  a  daughter  whom 
the  Duke  of  Devonshire  declared  to  be  the  most  beautiful 
girl  he  ever  saw."  This  was  before  he  had  made  the  acquaint- 
ance of  the  family.  Airy  was  at  this  time  on  a  walking 


FROM  B.A.  DEGREE  TO  PLUMIAN   PROFESSORSHIP.       57 

tour  in  Derbyshire  with  his  brother  William,  and  they  were 
received  at  Edensor  by  Mr  Smith,  to  whom  he  had  letters 
of  introduction.  He  seems  to  have  fallen  in  love  with  Miss 
Smith  "  at  first  sight,"  and  within  two  days  of  first  seeing  her 
he  made  her  an  offer  of  marriage.  Neither  his  means  nor  his 
prospects  at  that  time  permitted  the  least  idea  of  an  imme- 
diate marriage,  and  Mr  Smith  would  not  hear  of  any  engage- 
ment. But  he  never  had  the  least  doubt  as  to  the  wisdom  of 
the  choice  that  he  had  made  :  he  worked  steadily  on,  winning 
fame  and  position,  and  recommending  his  suit  from  time  to 
time  to  Miss  Smith  as  opportunity  offered,  and  finally  mar- 
ried her,  nearly  six  years  after  his  first  proposal.  His  con- 
stancy had  its  reward,  for  he  gained  a  most  charming  and 
affectionate  wife.  As  he  records  at  the  time  of  his  marriage, 
"My  wife  was  aged  between  25  and  26,  but  she  scarcely 
appeared  more  than  18  or  20.  Her  beauty  and  accomplish- 
ments, her  skill  and  fidelity  in  sketching,  and  above  all  her 
exquisite  singing  of  ballads,  made  a  great  sensation  in  Cam- 
bridge." 

Their  married  life  lasted  45  years,  but  the  last  six  years 
were  saddened  by  the  partial  paralysis  and  serious  illness  of 
Lady  Airy.  The  entire  correspondence  between  them  was 
most  carefully  preserved,  and  is  a  record  of  a  most  happy 
union.  The  letters  were  written  during  his  numerous  journeys 
and  excursions  on  business  or  pleasure,  and  it  is  evident  that 
his  thoughts  were  with  her  from  the  moment  of  their  parting. 
Every  opportunity  of  writing  was  seized  with  an  energy  and 
avidity  that  shewed  how  much  his  heart  was  in  the  corre- 
spondence. Nothing  was  too  trivial  or  too  important  to 
communicate  to  his  wife,  whether  relating  to  family  or  business 
matters.  The  letters  on  both  sides  are  always  full  of  affection 
and  sympathy,  and  are  written  in  that  spirit  of  confidence 
which  arises  from  a  deep  sense  of  the  value  and  necessity  of 
mutual  support  in  the  troubles  of  life.  And  with  his  active 
and  varied  employments  and  his  numerous  family  there  was 
no  lack  of  troubles.  They  were  both  of  them  simple-minded, 


58  GEORGE   BIDDELL  AIRY. 

sensible,  and  practical  people,  and  were  very  grateful  for  such 
comforts  and  advantages  as  they  were  able  to  command,  but 
for  nothing  in  comparison  with  their  deep  respect  and  affec- 
tion for  one  another. 

Both  by  natural  ability  and '  education  she  was  well 
qualified  to  enter  into  the  pursuits  of  her  husband,  and  in 
many  cases  to  assist  him.  She  always  welcomed  her  hus- 
band's friends,  and  by  her  skill  and  attractive  courtesy  kept 
them  well  together.  She  was  an  admirable  letter-writer,  and 
in  the  midst  of  her  numerous  domestic  distractions  always 
found  time  for  the  duties  of  correspondence.  In  conversation 
she  was  very  attractive,  not  so  much  from  the  wit  or  brilliancy 
of  her  remarks  as  from  the  brightness  and  interest  with  which 
she  entered  into  the  topics  under  discussion,  and  from  the 
unfailing  grace  and  courtesy  with  which  she  attended  to  the 
views  of  others.  This  was  especially  recognized  by  the 
foreign  astronomers  and  men  of  science  who  from  time  to 
time  stayed  as  guests  at  the  Observatory  and  to  whom  she 
acted  as  hostess.  Although  she  was  not  an  accomplished 
linguist  yet  she  was  well  able  to  express  herself  in  French 
and  German,  and  her  natural  good  sense  and  kindliness 
placed  her  guests  at  their  ease,  and  made  them  feel  them- 
selves (as  indeed  they  were)  welcomed  and  at  home. 

Her  father,  the  Rev.  Richard  Smith,  was  a  man  of  most 
cultivated  mind,  and  of  the  highest  principles,  with  a  keen 
enjoyment  of  good  society,  which  the  confidence  and  friend- 
ship of  his  patron  the  Duke  of  Devonshire  amply  secured  to 
him,  both  at  Chatsworth  and  in  London.  He  had  a  deep 
attachment  to  his  Alma  Mater  of  Cambridge,  and  though  not 
himself  a  mathematician  he  had  a  great  respect  for  the 
science  of  mathematics  and  for  eminent  mathematicians. 
During  the  long  courtship  already  related  Mr  Smith  con- 
ceived the  highest  respect  for  Airy's  character,  as  well  as 
for  his  great  repute  and  attainments,  and  expressed  his  lively 
satisfaction  at  his  daughter's  marriage.  Thus  on  January  2Oth, 
1830,  he  wrote  to  his  intended  son-in-law  as  follows :  "  I  have 


FROM  B.A.   DEGREE  TO  PLUMIAN    PROFESSORSHIP.       59 

little  else  to  say  to  you  than  that  I  continue  with  heartfelt 
satisfaction  to  reflect  on  the  important  change  about  to  take 
place  in  my  dear  daughter's  situation.  A  father  must  not 
allow  himself  to  dilate  on  such  a  subject :  of  course  I  feel 
confident  that  you  will  have  no  reason  to  repent  the  irre- 
vocable step  you  have  taken,  but  from  the  manner  in  which 
Richarda  has  been  brought  up,  you  will  find  such  a  helpmate 
in  her  as  a  man  of  sense  and  affection  would  wish  to  have, 
and  that  she  is  well  prepared  to  meet  the  duties  and  trials 
(for  such  must  be  met  with)  of  domestic  life  with  a  firm  and 
cultivated  mind,  and  the  warm  feelings  of  a  kind  heart.  Her 
habits  are  such  as  by  no  means  to  lead  her  to  expensive 
wishes,  nor  will  you  I  trust  ever  find  it  necessary  to  neglect 
those  studies  and  pursuits  upon  which  your  reputation  and 
subsistence  are  chiefly  founded,  to  seek  for  idle  amusements 
for  your  companion.  I  must  indulge  no  further  in  speaking 
of  her,  and  have  only  at  present  to  add  that  I  commit  in  full 
confidence  into  your  hands  the  guardianship  of  my  daughter's 
happiness."  And  on  April  5th,  1830,  shortly  after  their 
marriage,  he  wrote  to  his  daughter  thus :  "  If  thinking  of  you 
could  supply  your  place  amongst  us  you  would  have  been 
with  us  unceasingly,  for  we  have  all  of  us  made  you  the 
principal  object  of  our  thoughts  and  our  talk  since  you  left 
us,  and  I  travelled  with  you  all  your  journey  to  your  present 
delightful  home.  We  had  all  but  one  feeling  of  the  purest 
pleasure  in  the  prospect  of  the  true  domestic  comfort  to 
which  we  fully  believe  you  to  be  now  gone,  and  we  rejoice 
that  all  your  endearing  qualities  will  now  be  employed  to 
promote  the  happiness  of  one  whom  we  think  so  worthy  of 
them  as  your  dear  husband,  who  has  left  us  in  the  best 
opinion  of  his  good  heart,  as  well  as  his  enlightened  and 
sound  understanding.  His  late  stay  with  us  has  endeared 
him  to  us  all.  Never  did  man  enter  into  the  married  state 
from  more  honourable  motives,  or  from  a  heart  more  truly 
seeking  the  genuine  happiness  of  that  state  than  Mr  Airy, 
and  he  will,  I  trust,  find  his  reward  in  you  from  all  that  a 


60  GEORGE   BIDDELL  AIRY. 

good  wife  can  render  to  the  best  of  husbands,  and  his  hap- 
piness be  reflected  on  yourself."  It  would  be  difficult  to  find 
letters  of  more  genuine  feeling  and  satisfaction,  or  more 
eloquently  expressed,  than  these. 

The  narrative  of  the  Autobiography  will  now  be  resumed. 

"  I  had  been  disappointed  two  years  before  of  an  expe- 
dition to  Derbyshire.  I  had  wished  still  to  make  it,  and  my 
brother  wished  to  go :  and  we  determined  to  make  it  this 
year  (1824).  We  were  prepared  with  walking  dresses  and 
knapsacks.  I  had  well  considered  every  detail  of  our  route, 
and  was  well  provided  with  letters  of  introduction,  including 
one  to  the  Rev.  R.  Smith  of  Edensor.  On  June  29th  we 
started  by  coach  to  Newmarket  and  walked  through  the  Fens 
by  Ramsay  to  Peterborough.  Then  by  Stamford  and  Ketton 
quarries  to  Leicester  and  Derby.  Here  we  were  recognized 
by  a  Mr  Calvert,  who  had  seen  me  take  my  degree,  and  he 
invited  us  to  breakfast,  and  employed  himself  in  shewing  us 
several  manufactories,  &c.  to  which  we  had  been  denied 
access  when  presenting  ourselves  unsupported.  We  then 
went  to  Belper  with  an  introduction  from  Mr  Calvert  to 
Jedediah  Strutt:  saw  the  great  cotton  mills,  and  in  the 
evening  walked  to  Matlock.  Up  to  this  time  the  country  of 
greatest  interest  was  the  region  of  the  fens  about  Ramsay  (a 
most  remarkable  district),  but  now  began  beauty  of  scenery. 
On  July  pth  we  walked  by  Rowsley  and  Haddon  Hall  over 
the  hills  to  Edensor,  where  we  stayed  till  the  I2th  with 
Mr  Smith.  We  next  visited  Hathersage,  Castleton,  and 
Marple  (where  I  wished  to  see  the  canal  aqueduct),  and 
went  by  coach  to  Manchester,  and  afterwards  to  Liverpool. 
Here  Dr  Traill  recommended  us  to  -see  the  Pontycyssylte 
Aqueduct,  and  we  went  by  Chester  and  -Wrexham  to 
Rhuabon,  saw  the  magnificent  work,  and  proceeded  to 
Llangollen.  Thence  by  Chester  and  Northwich  (where  we 
descended  a  salt-mine)  to  Macclesfield.  Then  to  the  Ecton 
mine  (of  which  we  saw  but  little)  through  Dovedale  to 


FROM   B.A.   DEGREE  TO   PLUMIAN   PROFESSORSHIP.       6 1 

Ashbourn,  and  by  coach  to  Derby.  On  July  24th  to 
Birmingham,  where  we  found  Mr  Guest,  lodged  in  his  house, 
and  were  joined  by  my  pupil  Guest.  Here  we  were  fully 
employed  in  visiting  the  manufactures,  and  then  went  into 
the  iron  country,  where  I  descended  a  pit  in  the  Staffordshire 
Main.  Thence  by  coach  to  Cambridge,  where  I  stopped  to 
prepare  for  the  Fellowship  Examination. 

"  I  had  two  pupils  in  this  portion  of  the  Long  Vacation, 
Turner  and  Dobbs.  On  August  2nd  my  writing  of  Latin 
began  regularly  as  before.  My  principal  mathematics  on  the 
quires  are  Optics.  On  August  25th  I  made  experiments  on 
my  left  eye,  with  good  measures,  and  on  Aug.  26th  ordered 
a  cylindrical  lens  of  Peters,  a  silversmith  in  the  town,  which 
I  believe  was  never  made.  Subsequently,  while  at  Playford, 
I  ordered  cylindrical  lenses  of  an  artist  named  Fuller,  living 
at  Ipswich,  and  these  were  completed  in  November,  1824. 

"  My  letter  to  the  Examiners,  announcing  my  intention  of 
sitting  for  Fellowship  (which  like  all  other  such  documents  is 
preserved  on  my  quires)  was  delivered  on  Sept.  2ist.  The 
Examination  took  place  on  Sept.  22nd  and  the  two  following 
days.  On  Oct.  1st,  1824,  at  the  usual  hour  of  the  morning,  I 
was  elected  Fellow.  There  were  elected  at  the  same  time 
T.  B.  Macaulay  (afterwards  Lord  Macaulay),  who  was  a  year 
senior  to  me  in  College,  and  I  think  Field  of  my  own  year. 
I  drew  up  my  letter  of  acknowledgment  to  the  Electors.  On 
Oct.  2nd  at  9  in  the  morning  I  was  admitted  Fellow  with 
the  usual  ceremonies,  and  at  10  I  called  on  the  Electors  with 
my  letter  of  acknowledgment.  I  immediately  journeyed  to 
Derbyshire,  paid  a  visit  at  Edensor,  and  returned  by  Sheffield. 

"On  Oct.  nth  (it  having  been  understood  with  Mr 
Higman  that  my  engagement  as  Assistant  Mathematical 
Tutor  stood)  the  Master  sent  for  me  to  appoint  me  and  to 
say  what  was  expected  as  duty  of  the  office.  He  held  out  to 
me  the  prospect  of  ultimately  succeeding  to  the  Tutorship, 
and  I  told  him  that  I  hoped  to  be  out  of  College  before  that 
time. 


62  GEORGE   BIDDELL  AIRY. 

"  About  this  time  the  '  Athenaeum,'  a  club  of  a  scientific 
character,  was  established  in  London,  and  I  was  nominated 
on  it,  but  I  declined .  (Oct.  I4th).  In  this  year  (1824)  I 
commenced  account  with  a  banker  by  placing  £110  in  the 
hands  of  Messrs  Mortlock  and  Co".  On  Oct.  i6th  I  walked 
to  Bury,  and  after  a  single  day's  stay  there  returned  to 
Cambridge. 

"On  Oct.  23rd,  1824, 1  began  my  lectures  as  Mathematical 
Assistant  Tutor.  I  lectured  the  Senior  Sophs  and  Junior 
Sophs  on  Higman's  side.  The  number  of  Senior  Sophs  was 
21.  Besides  this  I  took  part  in  the  'Examinations  of  the 
Questionists,'  a  series  of  exercises  for  those  who  were  to  take 
the  Bachelor's  degree  in  the  next  January.  I  examined  in 
Mechanics,  Newton,  and  Optics.  I  had  also  as  private 
pupils  Turner,  Dobbs,  and  Cooper.  I  now  ceased  from  the 
exercise  which  I  had  followed  with  such  regularity  for 
five  years,  namely  that  of  daily  writing  Latin.  In  its  stead 
I  engaged  a  French  Master  (Goussel)  with  whom  I  studied 
French  with  reasonable  assiduity  for  the  three  terms  to 
June,  1825. 

"  Among  mathematical  investigations  I  find :  Theory  of 
the  Moon's  brightness,  Motion  of  a  body  in  an  ellipse  round 
two  centres  of  force,  Various  differential  equations,  Numerical 
computation  of  sin  TT  from  series,  Numerical  computation  of 
sines  of  various  arcs  to  18  decimals,  Curvature  of  surfaces  in 
various  directions,  Generating  functions,  Problem  of  sound. 
I  began  in  the  winter  a  Latin  Essay  as  competing  for  the 
Middle  Bachelors'  Prize,  but  did  not  proceed  with  it.  I 
afterwards  wished  that  I  had  followed  it  up :  but  my  time 
was  fully  occupied. 

"On  Jan.  28th,  1825,  I  started  for  Edensor,  where  I  paid 
a  visit,  and  returned  on  Feb.  2nd.  On  Feb.  4th  I  wrote  to 
Mr  Clarkson,  asking  his  advice  about  a  profession  or  mode 
of  life  (the  cares  of  life  were  now  beginning  to  press  me 
heavily,  and  continued  to  do  so  for  several  years).  He  re- 
plied very  kindly,  but  his  answer  amounted  to  nothing. 


FROM   B.A.   DEGREE  TO   PLUMIAN   PROFESSORSHIP.       63 

About  the  same  time  I  had  some  conversation  of  the  same 
kind  with  Mr  Peacock,  which  was  equally  fruitless. 

"  On  Feb.  4th  I  have  investigations  of  the  density  of  light 
near  a  caustic  (on  the  theory  of  emissions).  On  Feb.  5th  I 
finished  a  Paper  about  the  defect  in  my  eye,  which  was  com- 
municated to  the  Cambridge  Philosophical  Society  on  Feb. 
2 1  st.  Mr  Peacock  or  Mr  Whewell  had  some  time  previously 
applied  to  me  to  write  a  Paper  on  Trigonometry  for  the 
Encyclopaedia  Metropolitana,  and  I  had  been  collecting  some 
materials  (especially  in  regard  to  its  history)  at  every  visit  to 
London,  where  I  read  sometimes  at  the  British  Museum: 
also  in  the  Cambridge  libraries.  I  began  this  Paper  (roughly) 
on  Feb.  8th,  and  finished  it  on  Mar.  3rd.  The  history  of 
which  I  speak,  by  some  odd  management  of  the  Editors  of 
the  Encyclopaedia,  was  never  published.  The  MS.  is  now 
amongst  the  MSS.  of  the  Royal  Observatory,  Greenwich. 
Other  subjects  on  my  quires  are :  Theory  of  musical  con- 
cords, many  things  relating  to  trigonometry  and  trigono- 
metrical tables,  achromatic  eye-pieces,  equation  to  the  surface 
bounding  the  rays  that  enter  my  left  eye,  experiments  on 
percussion.  Also  notes  on  Cumberland  and  Wales  (I  had 
already  proposed  to  myself  to  take  a  party  of  pupils  in 
the  Long  Vacation  to  Keswick),  and  notes  on  history  and 
geology. 

"I  had  been  in  correspondence  with  Dr  Malkin  (master 
of  Bury  School),  who  on  Feb.  8th  sent  a  certificate  for  my 
brother  William,  whom  I  entered  at  Trinity  on  Peacock's 
side.  On  Mar.  25th  I  changed  my  rooms,  quitting  those  on 
the  ground-floor  east  side  of  Queen  Mary's  Gate  for  first- 
floor  rooms  in  Neville's  Court,  south  side,  the  easternmost 
rooms.  In  this  term  my  lectures  lasted  from  Apr.  i8th  to 
May  I4th.  Apparently  I  had  only  the  Senior  Sophs,  19  in 
number,  and  the  same  four  pupils  (Turner,  Dobbs,  Cooper, 
Hovenden)  as  in  the  preceding  term.  The  only  scientific 
subjects  on  which  I  find  notes  are,  a  Paper  on  the  forms  of 
the  Teeth  of  Wheels,  communicated  to  the  Philosophical 


64  GEORGE  BIDDELL  AIRY. 

Society  on  May  2nd  ;  some  notes  about  Musical  Concords, 
and  some  examination  of  a  strange  piece  of  Iceland  Spar. 
On  Apr.  29th  I  was  elected  to  the  Northern  Institution  (of 
Inverness) ;  the  first  compliment  that  I  received  from  an 
extraneous  body. 

"On  May  I4th  I  have  a  most  careful  examination  of  my 
money  accounts,  to  see  whether  I  can  make  an  expedition 
with  my  sister  into  Wales.  My  sister  came  to  Cambridge, 
and  on  Monday,  May  23rd,  1825,  we  started  for  Wales, 
equipped  in  the  lightest  way  for  a  walking  expedition.  We 
went  by  Birmingham  to  Shrewsbury :  then  to  the  Pontycys- 
sylte  Aqueduct  and  by  various  places  to  Bala,  and  thence  by 
Llanrwst  to  Conway.  Here  the  suspension  bridge  was  under 
construction :  the  mole  was  made  and  the  piers,  but  nothing 
else.  Then  on  to  Bangor,  where  nine  chains  of  the  suspen- 
sion bridge  were  in  place,  and  so  to  Holyhead.  Then  by 
Carnarvon  to  Bethgelert,  ascending  Snowdon  by  the  way, 
and  in  succession  by  Festiniog,  Dolgelly,  and  Aberystwyth 
to  Hereford  (the  first  time  that  I  had  visited  it  since  my 
father  left  it).  From  thence  we  went  by  coach  to  London, 
and  I  went  on  to  Cambridge  on  the  23rd  of  June. 

"  I  had  arranged  to  take  a  party  of  pupils  to  Keswick, 
and  to  take  my  brother  there.  Mr  Clarkson  had  provided 
me  with  introductions  to  Mr  Southey  and  Mr  Wordsworth. 
On  Wednesday,  June  29th,  1825,  we  started,  and  went  by 
Leicester,  Sheffield,  Leeds,  and  Kendal,  to  Keswick,  calling 
at  Edensor  on  the  way.  My  pupils  were  Cleasby,  Marshman, 
Clinton,  Wigram,  Tottenham,  and  M.  Smith.  At  Keswick  I 
passed  three  months  very  happily.  I  saw  Mr  Southey's 
family  frequently,  and  Mr  Wordsworth's  occasionally.  By 
continual  excursions  in  the  neighbourhood,  and  by  a  few 
excursions  to  places  as  distant  as  Bowness,  Calder  Bridge, 
&c.  (always  climbing  the  intermediate  mountains),  I  became 
well  acquainted  with  almost  the  whole  of  that  beautiful 
country,  excepting  some  of  the  S.  W.  dales.  A  geological 
hammer  and  a  mountain  barometer  were  very  interesting 


FROM   B.A.   DEGREE  TO   PLUMIAN    PROFESSORSHIP.       65 

companions.  I  had  plenty  of  work  with  my  pupils  :  I  worked 
a  little  Lunar  Theory,  a  little  of  Laplace's  Equations,  some- 
thing of  the  Figure  of  the  Earth,  and  I  wrote  out  very  care- 
fully my  Trigonometry  for  the  Encyclopaedia  Metropolitana. 
I  read  a  little  of  Machiavelli,  and  various  books  which  I  bor- 
rowed of  Mr  Southey.  On  Friday,  Sept  3Oth,  my  brother  and 
I  left  for  Kendal,  and  after  a  stay  of  a  few  days  at  Edensor, 
arrived  at  Cambridge  on  Oct.  nth. 

"On  Oct.  2 1st  my  Lectures  to  the  Junior  Sophs  began, 
39  names,  lasting  to  Dec.  I3th.  Those  to  the  Senior  Sophs, 
16  names,  Oct  2Qth  to  Dec.  loth.  I  also  examined  Ques- 
tionists  as  last  year.  I  have  notes  about  a  Paper  on  the  con- 
nection of  impact  and  pressure,  read  at  the  Philosophical 
Society  on  Nov.  I4th,  but  not  printed,  dipping-needle  prob- 
lems, curve  described  round  three  centres  of  force,  barometer 
observations,  theory  of  the  Figure  of  the  Earth  with  variable 
density,  and  effect  on  the  Moon,  correction  to  the  Madras 
pendulum,  wedge  with  friction,  spots  seen  in  my  eyes,  density 
of  rays  near  a  caustic.  In  this  term  I  accomplished  the  pre- 
paration of  a  volume  of  Mathematical  Tracts  on  subjects 
which,  either  from  their  absolute  deficiency  in  the  University 
or  from  the  unreadable  form  in  which  they  had  been  pre- 
sented, appeared  to  be  wanted.  The  subjects  of  my  Tracts 
were,  Lunar  Theory  (begun  Oct.  26th,  finished  Nov.  1st), 
Figure  of  the  Earth  (ist  part  finished  Nov.  i8th),  Precession 
and  Nutation  (my  old  MS.  put  in  order),  and  the  Calculus  of 
Variations.  I  applied,  as  is  frequently  done,  to  the  Syndicate 
of  the  University  Press  for  assistance  in  publishing  the  work ; 
and  they  agreed  to  give  me  paper  and  printing  for  500  copies. 
This  notice  was  received  from  Professor  Turton  on  Nov.  29th, 
1825.  It  was  probably  also  in  this  year  that  I  drew  up  an 
imperfect  'Review'  of  Coddington's  Optics,  a  work  which 
deserved  severe  censure :  my  review  was  never  finished. 

"  In  the  Long  Vacation  at  Keswick  I  had  six  pupils  at 
£42  each.  In  the  October  term  I  had  Marshman  and 
Ogilby  at  £105  for  three  terms,  and  Dobbs  at  £75  for  three 
A.  B.  5 


66  GEORGE   BIDDELL  AIRY. 

terms.  I  had,  at  Mr  Peacock's  suggestion,  raised  my  rate 
from  60  to  100  guineas  for  three  terms:  this  prevented  some 
from  applying  to  me,  and  induced  some  to  withdraw  who  had 
been  connected  with  me :  but  it  .did  me  no  real  hurt,  for 
engrossment  by  pupils  is  the  w6rst  of  all  things  that  can 
happen  to  a  man  who  hopes  to  distinguish  himself.  On  Dec. 
1 7th  I  went  to  Bury,  and  returned  to  Cambridge  on  Jan. 
30th,  1826. 

"I  have  the  attendance-bills  of  my  Lectures  to  Senior 
Sophs  (16)  from  Feb.  3rd  to  Feb.  23rd,  and  to  Freshmen  (40) 
from  Feb.  2;th  to  Mar.  15.  It  would  appear  that  I  gave  but 
one  college-lecture  per  day  (my  belief  was  that  I  always  had 
two).  The  tutor's  stipend  per  term  was  £50.  On  my  quires 
I  find,  Investigations  for  the  ellipticity  of  a  heterogeneous 

spheroid  when  the  density  is  expressed  by  -  — —  (the  remark- 
able properties  of  which  I  believe  I  discovered  entirely  myself, 
although  they  had  been  discovered  by  other  persons),  Theo- 
retical Numbers  for  precession,  nutation,  &c.,  some  investiga- 
tions using  Laplace's  Y,  hard  work  on  the  Figure  of  the 
Earth  to  the  2nd  order,  '  Woodhouse's  remaining  apparatus/ 
Notes  about  Lambton's  and  Kater's  errors,  Depolarization, 
Notes  of  Papers  on  depolarization  in  the  Phil.  Trans.,  Mag- 
netic Investigations  for  Lieut.  Foster,  Isochronous  Oscilla- 
tions in  a  resisting  medium,  Observations  on  a  strange  piece 
of  Iceland  Spar.  On  Mar.  /th  forwarded  Preface  and  Title 
Page  for  my  Mathematical  Tracts. 

"  Some  time  in  this  term  I  began  to  think  of  the  possi- 
bility of  observing  the  diminution  of  gravity  in  a  deep  mine, 
and  communicated  with  Whewell,  who  was  disposed  to  join 
in  experiments.  My  first  notion  was  simply  to  try  the  rate 
of  a  clock,  and  the  Ecton  mine  was  first  thought  of.  I  made 
enquiries  about  the  Ecton  mine  through  Mr  Smith  (of  Eden- 
sor),  and  visited  the  mine,  but  in  the  meantime  Whewell  had 
made  enquiries  in  London  and  found  (principally  from  Dr 
Paris)  that  the  mine  of  Dolcoath  near  Camborne  in  Cornwall 


FROM   B.A.   DEGREE   TO   PLUMIAN    PROFESSORSHIP.       67 

would  be  a  better  place  for  the  experiment.  Dr  Paris  wrote 
to  me  repeatedly,  and  ultimately  we  resolved  on  trying  it 
there.  In  my  papers  on  Mar.  2ist  are  various  investigations 
about  attractions  in  both  mines.  On  Apr.  3rd  I  went  to 
London,  principally  to  arrange  about  Dolcoath,  and  during 
April  and  May  I  was  engaged  in  correspondence  with  Sir  H. 
Davy  (President  of  the  Royal  Society),  Mr  Herschel,  and  Dr 
Young  (Secretary  of  the  Board  of  Longitude)  about  the  loan 
of  instruments  and  pendulums.  On  Apr.  23rd  I  was  prac- 
tising pendulum-observations  (by  coincidence);  and  about 
this  time  repeatedly  practised  transits  with  a  small  instru- 
ment lent  by  Mr  Sheepshanks  (with  whom  my  acquaintance 
must  have  begun  no  long  time  before)  which  was  erected 
under  a  tent  in  the  Fellows'  Walks.  On  my  quires  I  find 
various  schemes  for  graduating  thermometers  for  pendulum 
experiments. 

"  I  find  also  Notes  of  examination  of  my  brother  William, 
who  had  come  to  College  last  October ;  and  a  great  deal  of 
correspondence  with  my  mother  and  sister  and  Mr  Case,  a 
lawyer,  about  a  troublesome  business  with  Mr  Cropley,  an 
old  friend  of  G.  Biddell,  to  whom  my  father  had  lent  ^"500 
and  whose  affairs  were  in  Chancery. 

"  My  lectures  in  this  term  were  to  the  Junior  Sophs  from 
Apr.  loth  to  May  I3th  :  they  were  six  in  number  and  not 
very  regular.  On  Apr.  28th  I  sent  to  Mawman  the  copy  of 
my  Trigonometry  for  the  Encyclopaedia  Metropolitana,  for 
which  I  received  £42.  I  received  notice  from  the  Press  Syn- 
dicate that  the  price  of  my  Mathematical  Tracts  was  fixed  at 
6s.  6d. :  I  sold  the  edition  to  Deighton  for  £70,  and  it  was 
immediately  published.  About  this  time  I  have  letters  from 
Mr  Herschel  and  Sir  H.  Davy  about  a  Paper  to  be  presented 
to  the  Royal  Society — I  suppose  about  the  Figure  of  the 
Earth  to  the  2nd  order  of  ellipticity,  which  was  read  to  the 
Royal  Society  on  June  I5th. 

"On  Saturday,  May  I3th,  1826,  I  went  to  London  on  the 
way  to  Dolcoath,  and  received  four  chronometers  from  the 

5—2 


68  GEORGE  BIDDELL  AIRY. 

Royal  Observatory,  Greenwich.  I  travelled  by  Devonport 
and  Falmouth  to  Camborne,  where  I  arrived  on  May  2Oth 
and  dined  at  the  count-house  dinner  at  the  mine.  I  was 
accompanied  by  Ibbotson,  who  was  engaged  as  a  pupil,  and 
intended  for  an  engineer.  On  May  24th  Whewell  arrived, 
and  we  took  a  pendulum  and  clock  down,  and  on  the  3<Dth 
commenced  the  observation  of  coincidences  in  earnest.  This 
work,  with  the  changing  of  the  pendulums,  and  sundry  short 
expeditions,  occupied  nearly  three  weeks.  We  had  continued 
the  computation  of  our  observations  at  every  possible  interval. 
It  is  to  be  understood  that  we  had  one  detached  pendulum 
swinging  in  front  of  a  clock  pendulum  above,  and  another 
similarly  mounted  below ;  and  that  the  clocks  were  compared 
by  chronometers  compared  above,  carried  down  and  com- 
pared, compared  before  leaving,  and  brought  up  and  com- 
pared. The  upper  and  lower  pendulums  had  been  inter- 
changed. It  was  found  now  that  the  reliance  on  the  steadi- 
ness of  the  chronometers  was  too  great ;  and  a  new  method 
was  devised,  in  which  for  each  series  the  chronometers  should 
make  four  journeys  and  have  four  comparisons  above  and 
two  below.  This  arrangement  commenced  on  the  ipth  June 
and  continued  till  the  26th.  On  the  26th  we  packed  the  lower 
instruments,  intending  to  compare  the  pendulum  directly 
with  the  upper  one,  and  sent  them  up  the  shaft:  when  an 
inexplicable  occurrence  stopped  all  proceedings.  The  basket 
containing  all  the  important  instruments  was  brought  up  to 
the  surface  (in  my  presence)  on  fire  ;  some  of  the  instruments 
had  fallen  out  with  their  cases  burning.  Whether  a  super- 
stitious miner  had  intentionally  fired  it,  or  whether  the  snuff 
of  a  candle  had  been  thrown  into  it,  is  not  known.  Our 
labour  was  now  rendered  useless.  On  the  28th  I  packed  up 
what  remained  of  instruments,  left  for  Truro,  and  arrived  at 
Bury  on  July  1st.  During  our  stay  in  Cornwall  I  had 
attended  a  'ticketing'  or  sale  of  ore  at  Camborne,  and  we 
had  made  expeditions  to  the  N.  W.  Coast,  to  Portreath  and 
Illogan,  to  Marazion  and  St  Michael's  Mount,  and  to  Pen- 


FROM   B.A.   DEGREE  TO   PLUMIAN    PROFESSORSHIP.       69 

zance  and  the  Land's  End.  On  July  3rd  I  saw  Mr  Cropley 
in  Bury  gaol,  and  went  to  Cambridge.  On  the  4th  I  was 
admitted  A.M.,  and  on  the  5th  was  admitted  Major  Fellow. 

"  I  had  engaged  with  four  pupils  to  go  to  Orleans  in  this 
Long  Vacation  :  my  brother  William  was  also  to  go.  One  of 
my  pupils,  Dobbs,  did  not  join  :  the  other  three  were  Tinkler, 
Ogilby,  and  Ibbotson.  We  left  London  on  July  9th,  and 
travelled  by  Brighton,  Dieppe,  Rouen,  and  Paris  to  Orleans. 
At  Paris  I  saw  Bouvard,  Pouillet,  Laplace  and  Arago.  I  had 
introductions  from  Mr  Peacock,  Mr  South,  Mr  Herschel,  Dr 
Young ;  and  from  Professor  Sedgwick  to  an  English  resi- 
dent, Mr  Underwood.  On  the  I9th  I  was  established  in  the 
house  of  M.  Lagarde,  Protestant  Minister.  Here  I  received 
my  pupils.  On  the  28th  I  commenced  Italian  with  an  Italian 
master :  perhaps  I  might  have  done  more  prudently  in  adher- 
ing to  French,  for  I  made  no  great  progress.  On  Aug.  2nd 
I  saw  a  murderer  guillotined  in  the  Place  Martroi.  The 
principal  investigations  on  my  quires  are — Investigations 
about  pendulums,  Calculus  of  Variations,  Notes  for  the 
Figure  of  the  Earth  (Encyc.  Metrop.)  and  commencement 
of  the  article,  steam-engine  machinery,  &c.  I  picked  up 
various  French  ballads,  read  various  books,  got  copies  of 
the  Marseillaise  (this  I  was  obliged  to  obtain  rather  secretly, 
as  the  legitimist  power  under  Charles  X.  was  then  at  its 
height)  and  other  music,  and  particulars  of  farm  wages  for 
Whewell  and  R.  Jones.  The  summer  was  intensely  hot,  and 
I  believe  that  the  heat  and  the  work  in  Dolcoath  had  weak- 
ened me  a  good  deal.  The  family  was  the  old  clergyman, 
his  wife,  his  daughter,  and  finally  his  son.  We  lived  together 
very  amicably.  My  brother  lodged  in  a  Cafe  in  the  Place 
Martroi ;  the  others  in  different  families.  I  left  Orleans  on 
Sept.  30th  for  Paris.  Here  I  attended  the  Institut,  and  was 
present  at  one  of  Ampere's  Lectures.  I  arrived  at  Cambridge 
on  Oct.  1 4th. 

"On  Oct.  i6th  Whewell  mentioned  to  me  that  the  Lu- 
casian  Professorship  would  be  immediately  vacated  by 


70  GEORGE   BIDDELL  AIRY. 

Turton,  and  encouraged  me  to  compete  for  it.  Shortly  after- 
wards Mr  Higman  mentioned  the  Professorship,  and  Joshua 
King  (of  Queens')  spoke  on  the  restriction  which  prevented 
College  tutors  or  Assistant  tutors  from  holding  the  office. 
About  this  time  Mr  Peacock  rendered  me  a  very  important 
service.  As  the  emolument  of  the  Lucasian  Professorship 
was  only  £99,  and  that  of  the  Assistant  Tutorship  £150,  I 
had  determined  to  withdraw  from  the  candidature.  But  Mr 
Peacock  represented  to  me  the  advantage  of  position  which 
would  be  gained  by  obtaining  the  Professorship  (which  I  then 
instantly  saw),  and  I  continued  to  be  a  candidate.  I  wrote 
letters  to  the  Heads  of  Colleges  (the  electors)  and  canvassed 
them  personally.  Only  Dr  Davy,  the  Master  of  Caius 
College,  at  once  promised  me  his  vote.  Dr  French,  Master 
of  Jesus  College,  was  a  candidate ;  and  several  of  the  Heads 
had  promised  him  their  votes.  Mr  Babbage,  the  third  candi- 
date, threatened  legal  proceedings,  and  Dr  French  withdrew. 
The  course  was  now  open  for  Mr  Babbage  and  me. 

"In  the  meetings  of  the  Philosophical  Society  a  new 
mode  of  proceeding  was  introduced  this  term.  To  enliven 
the  meetings,  private  members  were  requested  to  give  oral 
lectures.  Mine  was  the  second,  I  think,  and  I  took  for 
subject  The  Machinery  of  the  Steam  Engines  in  the  Cornish 
mines,  and  especially  of  the  Pumping  Engines  and  Pumps. 
It  made  an  excellent  lecture :  the  subjects  were  at  that  time 
undescribed  in  books,  and  unknown  to  engineers  in  general 
out  of  Cornwall. 

"My  College  lectures  seem  to  have  been,  Oct.  2ist  to 
Dec.  I4th  to  31  Junior  Sophs,  Dec.  4th  to  I2th  to  12  Senior 
Sophs.  I  assisted  at  the  examinations  of  the  Questionists. 
I  had  no  private  pupils.  On  Nov.  26th  I  communicated  to 
the  Cambridge  Philosophical  Society  a  Paper  on  the  Theory 
of  Pendulums,  Balances,  and  Escapements :  and  I  find  appli- 
cations of  Babbage's  symbolism  to  an  escapement  which  I 
proposed.  I  have  various  investigations  about  the  Earth, 
supposed  to  project  at  middle  latitudes  above  the  elliptical 


FROM   B.A.   DEGREE  TO  PLUMIAN   PROFESSORSHIP.       71 

form.  In  November  an  account  of  the  Dolcoath  failure  (by 
Whewell)  was  given  to  the  Royal  Society. 

"At  length  on  Dec.  7th,  1826,  the  election  to  the  Lucasian 
Professorship  took  place:  I  was  elected  (I  think  unanimously) 
and  admitted.  I  believe  that  this  gave  great  satisfaction  to 
the  University  in  general.  My  uncle,  Arthur  Biddell,  was  in 
Cambridge  on  that  evening,  and  was  the  first  of  my  friends 
who  heard  of  it.  On  the  same  page  of  my  quires  on  which 
this  is  mentioned,  there  is  a  great  list  of  apparatus  to  be  con- 
structed for  Lucasian  Lectures,  notes  of  experiments  with 
Atwood's  Machine,  &c.  In  December,  correspondence  with 
Dollond  about  prisms.  I  immediately  issued  a  printed  notice 
that  I  would  give  professorial  lectures  in  the  next  Term. 

"On  Dec.  I3th  I  have  a  letter  from  Mr  Smith  informing 
me  of  the  dangerous  illness  (fever)  which  had  attacked  nearly 
every  member  of  his  family,  Richarda  worst  of  all.  On  Dec. 
23rd  I  went  to  Bury.  The  affairs  with  Cropley  had  been 
settled  by  the  sale  of  his  property  under  execution,  and  my 
father  did  not  lose  much  of  his  debt.  But  he  had  declined 
much  in  body  and  mind,  and  now  had  strange  hallucinations. 

"The  commencement  of  1827  found  me  in  a  better  posi- 
tion (not  in  money  but  in  prospects)  than  I  had  before  stood 
in:  yet  it  was  far  from  satisfactory.  I  had  resigned  my 
Assistant  Tutorship  of  £150  per  annum  together  with  the 
prospect  of  succeeding  to  a  Tutorship,  and  gained  only  the 
Lucasian  Professorship  of  £99  per  annum.  I  had  a  great 
aversion  to  entering  the  Church :  and  my  lay  fellowship 
would  expire  in  7  years.  My  prospects  in  the  law  or  other 
professions  might  have  been  good  if  I  could  have  waited  : 
but  then  I  must  have  been  in  a  state  of  starvation  probably 
for  many  years,  and  marriage  would  have  been  out  of  the 
question :  I  much  preferred  a  moderate  income  in  no  long 
time,  and  I  am  sure  that  in  this  I  judged  rightly  for  my  happi- 
ness. I  had  now  in  some  measure  taken  science  as  my  line 
(though  not  irrevocably),  and  I  thought  it  best  to  work  it 
well,  for  a  time  at  least,  and  wait  for  accidents. 


72  GEORGE   BIDDELL  AIRY. 

"  The  acceptance  of  the  Lucasian  Professorship  prevented 
me  from  being  pressed  by  Sedgwick  (who  was  Proctor  this 
year)  to  take  the  office  of  moderator :  which  was  a  great 
relief  to  me.  As  Lucasian  Professor  I  was  ipso  facto 
Member  of  the  Board  of  Longittfde.  A  stipend  of  £100  a 
year  was  attached  to  this,  on  condition  of  attending  four 
meetings :  but  I  had  good  reason  (from  intimations  by  South 
and  other  persons  in  London)  for  believing  that  this  would 
not  last  long.  The  fortnightly  notices  of  the  meetings  of 
the  Board  were  given  on  Jan.  i8th,  Mar.  22nd,  May  24th 
and  Oct.  i8th. 

"On  Jan.  2nd,  1827,  I  came  from  London  to  Bury.  I 
found  my  father  in  a  very  declining  state  (the  painful 
rheumatism  of  some  years  had  changed  to  ulcerations  of  the 
legs,  and  he  was  otherwise  helpless  and  had  distressing  hal- 
lucinations). On  Jan.  8th  I  walked  to  Cambridge.  At  both 
places  I  was  occupied  in  preparations  for  the  Smith's  Prize 
Examination  and  for  lectures  (for  the  latter  I  obtained  at 
Bury  gaol  some  numerical  results  about  tread-mills). 

"  Of  the  Smith's  Prize  I  was  officially  an  Examiner :  and 
I  determined  to  begin  with — what  had  never  been  done 
before — making  the  examination  public,  by  printing  the 
papers  of  questions.  The  Prize  is  the  highest  Mathematical 
honour  in  the  University :  the  competitors  are  incepting 
Bachelors  of  Arts  after  the  examination  for  that  Degree. 
My  day  of  examination  (apparently)  was  Jan.  2ist.  The 
candidates  were  Turner,  Cankrein,  Cleasby,  and  Mr  Gordon. 
The  first  three  had  been  my  private  pupils  :  Mr  Gordon  was 
a  Fellow-commoner  of  St  Peter's  College,  and  had  just  passed 
the  B.A.  examination  as  Senior  Wrangler,  Turner  being 
second.  My  situation  as  Examiner  was  rather  a  delicate 
one,  and  the  more  so  as,  when  I  came  to  examine  the  papers 
of  answers,  Turner  appeared  distinctly  the  first.  Late  at 
night  I  carried  the  papers  to  Whewell's  rooms,  and  he  on 
inspection  agreed  with  me.  The  other  examiners  (Professors 
Lax  and  Woodhouse,  Lowndean  and  Plumian  Professors) 


FROM  B.A.   DEGREE  TO   PLUMIAN   PROFESSORSHIP.       73 

generally  supported  me :  and  Turner  had  the  honour  of  First 
Smith's  Prize. 

"  On  Jan.  3Oth  my  mother  wrote,  asking  if  I  could  see 
Cropley  in  London,  where  he  was  imprisoned  for  contempt 
of  Chancery.  I  attended  the  meeting  of  the  Board  of 
Longitude  on  Feb.  ist,  and  afterwards  visited  Cropley  in  the 
Fleet  Prison.  He  died  there,  some  time  later.  It  was  by 
the  sale  of  his  effects  under  execution  that  my  father's  debt 
was  paid. 

"On  Feb.  i$th  I  communicated  to  the  Royal  Society  a 
Paper  on  the  correction  of  the  Solar  Tables  from  South's 
observations.  I  believe  that  I  had  alluded  to  this  at  the 
February  meeting  of  the  Board  of  Longitude,  and  that  in 
consequence  Mr  Pond,  the  Astronomer  Royal,  had  been  re- 
quested to  prepare  the  errors  of  the  Sun's  place  from  the 
Greenwich  observations :  which  were  supplied  some  months 
later.  With  the  exception  of  South's  Solar  Errors,  and 
some  investigations  about  dipping-needles,  I  do  not  find 
anything  going  on  but  matters  connected  with  my  ap- 
proaching lectures.  There  are  bridges,  trusses,  and  other 
mechanical  matters,  theoretical  and  practical,  without  end. 
Several  tradesmen  in  Cambridge  and  London  were  well  em- 
ployed. On  Feb.  I3th  I  have  a  letter  from  Cubitt  about 
groins  :  I  remember  studying  those  of  the  Custom-house  and 
other  places.  On  Feb.  2Oth  my  Syllabus  of  Lectures  was 
finished :  this  in  subsequent  years  was  greatly  improved.  I 
applied  to  the  Royal  Society  for  the  loan  of  Huyghens's 
object-glass,  but  they  declined  to  lend  it.  About  this  time  I 
find  observations  of  the  spectrum  of  Sirius. 

"  There  had  been  no  lectures  on  Experimental  Philosophy 
(Mechanics,  Hydrostatics,  Optics)  for  many  years.  The 
University  in  general,  I  believe,  looked  with  great  satisfac- 
tion to  my  vigorous  beginning :  still  there  was  considerable 
difficulty  about  it.  There  was  no  understood  term  for  the 
Lectures  :  no  understood  hour  of  the  day :  no  understood 
lecture  room.  I  began  this  year  in  the  Lent  Term,  but  in 


74  GEORGE  BIDDELL  AIRY. 

all  subsequent  years  I  took  the  Easter  Term,  mainly  for  the 
chance  of  sunlight  for  the  optical  experiments,  which  I  soon 
made  important.  I  could  get  no  room  but  a  private  or 
retiring  room  (not  a  regular  lecture  room)  in  the  buildings  at 
the  old  Botanic  Garden :  in  following  years  I  had  the  room 
under  the  University  Library.  The  Lectures  commenced  on 
some  day  in  February  1827:  I  think  that  the  number  who 
attended  them  was  about  64.  I  remember  very  well  that  the 
matter  which  I  had  prepared  as  an  Introductory  Lecture  did 
not  last  above  half  the  time  that  I  had  expected,  but  I 
managed  very  well  to  fill  up  the  hour.  On  another  occasion 
I  was  so  ill-prepared  that  I  had  contemplated  giving  notice 
that  I  was  unable  to  complete  the  hour's  lecture,  but  I  saw  in 
the  front  row  some  strangers,  introduced  by  some  of  my 
regular  attendants,  very  busy  in  taking  notes,  and  as  it  was 
evident  that  a  break-down  now  would  not  do,  I  silently 
exerted  myself  to  think  of  something,  and  made  a  very  good 
lecture. 

"On  Mar.  ist,  as  official  examiner,  I  received  notices 
from  14  candidates  for  Bell's  Scholarships,  and  prepared  my 
Paper  of  questions.  I  do  not  remember  my  day  of  examina- 
tion ;  but  I  had  all  the  answers  to  all  the  examiners'  ques- 
tions in  my  hands,  when  on  Mar.  2/th  I  received  notice  that 
my  father  had  died  the  preceding  evening.  This  stopped  my 
Lectures :  they  were  concluded  in  the  next  term.  I  think 
that  I  had  only  Mechanics  and  imperfect  Optics  this  term, 
no  Hydrostatics;  and  that  the  resumed  Lectures  were  princi- 
pally Optical.  They  terminated  about  May  I4th. 

"  With  my  brother  I  at  once  went  to  Bury  to  attend  my 
father's  funeral.  He  was  buried  on  Mar.  3ist,  1827,  in  the 
churchyard  of  Little  Whelnetham,  on  the  north  side  of  the 
church.  Shortly  afterwards  I  went  to  London,  and  on  Apr. 
5th  I  attended  a  meeting  of  the  Board  of  Longitude,  at  which 
Herschel  produced  a  Paper  regarding  improvements  of  the 
Nautical  Almanac.  Herschel  and  I  were  in  fact  the  leaders 
of  the  reforming  party  in  the  Board  of  Longitude  :  Dr  Young 


FROM   B.A.   DEGREE  TO   PLUMIAN   PROFESSORSHIP.       75 

the  Secretary  resisted  change  as  much  as  possible.  After  the 
meeting  I  went  to  Cambridge.  I  find  then  calculations  of 
achromatic  eye-pieces  for  a  very  nice  model  with  silk  threads 
of  various  colours  which  I  made  with  my  own  hands  for  my 
optical  lectures. 

"  On  Apr.  7th  Herschel  wrote  to  me  that  the  Professor- 
ship held  by  Dr  Brinkley  (then  appointed  Bishop  of  Cloyne) 
at  Dublin  would  be  vacant,  and  recommended  it  to  my 
notice,  and  sent  me  some  introductions.  I  reached  Dublin 
on  Apr.  1 5th,  where  I  was  received  with  great  kindness  by 
Dr  Brinkley  and  Dr  MacDonnell  (afterwards  Provost).  I 
there  met  the  then  Provost  Dr  Bartholomew  Lloyd,  Dr 
Lardner,  Mr  Hamilton  (afterwards  Sir  W.  R.  Hamilton)  and 
others.  In  a  few  days  I  found  that  they  greatly  desired  to 
appoint  Hamilton  if  possible  (they  did  in  fact  overcome  some 
difficulties  and  appoint  him  in  a  few  months),  and  that  they 
would  not  make  such  an  augmentation  as  would  induce  me 
to  offer  myself  as  a  candidate,  and  I  withdrew.  I  have 
always  remembered  with  gratitude  Dr  MacDonnell's  conduct, 
in  carefully  putting  me  on  a  fair  footing  in  this  matter.  I 
returned  by  Holyhead,  and  arrived  at  Birmingham  on  Apr. 
23rd.  While  waiting  there  and  looking  over  some  papers 
relating  to  the  spherical  aberration  of  eye-pieces,  in  which  I 
had  been  stopped  some  time  by  a  geometrical  difficulty,  I  did 
in  the  coffee-room  of  a  hotel  overcome  the  difficulty;  and 
this  was  the  foundation  of  a  capital  paper  on  the  Spherical 
Aberration  of  Eye-pieces.  This  paper  was  afterwards  pre- 
sented to  the  Cambridge  Philosophical  Society. 

"  About  this  time  a  circumstance  occurred  of  a  disagree- 
able nature,  which  however  did  not  much  disconcert  me. 
Mr  Ivory,  who  had  a  good  many  years  before  made  himself 
favourably  known  as  a  mathematician,  especially  by  his 
acquaintance  with  Laplace's  peculiar  analysis,  had  adopted 
(as  not  unfrequently  happens)  some  singular  hydrostatical 
theories.  In  my  last  Paper  on  the  Figure  of  the  Earth,  I 
had  said  that  I  could  not  receive  one  of  his  equations.  In 


76  GEORGE  BIDDELL  AIRY. 

the  Philosophical  Magazine  of  May  he  attacked  me  for  this 
with  great  heat.  On  May  8th  I  wrote  an  answer,  and  I 
think  it  soon  became  known  that  I  was  not  to  be  attacked 
with  impunity. 

"  Long  before  this  time  there1  had  been  some  proposal 
about  an  excursion  to  the  Lake  District  with  my  sister,  and 
I  now  arranged  to  carry  it  out.  On  May  23rd  I  went  to 
Bury  and  on  to  Playford  :  while  there  I  sketched  the  Cum- 
berland excursion.  On  June  5th  I  went  to  London,  I  believe 
to  the  Visitation  of  the  Greenwich  Observatory  to  which  I 
was  invited.  I  also  attended  the  meeting  of  the  Board  of 
Longitude.  I  think  it  was  here  that  Pond's  Errors  of  the 
Sun's  place  in  the  Nautical  Almanac  from  Greenwich  Obser- 
vations were  produced.  On  June  /th  I  went  by  coach  to 
Rugby,  where  I  met  my  sister,  and  we  travelled  to  Edensor. 
We  made  a  number  of  excursions  in  Derbyshire,  and  then 
passed  on  by  Penrith  to  Keswick,  where  we  arrived  on  June 
22nd.  From  Keswick  we  made  many  excursions  in  the 
Lake  District,  visited  Mr  Sou  they  and  Mr  Wordsworth, 
descended  a  coal  mine  at  Whitehaven,  and  returned  to 
Edensor  by  the  way  of  Ambleside,  Kendal,  and  Manchester. 
With  sundry  excursions  in  Derbyshire  our  trip  ended,  and 
we  returned  to  Cambridge  on  the  2ist  July. 

"  During  this  Long  Vacation  I  had  one  private  pupil, 
Crawford,  the  only  pupil  this  year,  and  the  last  that  I  ever 
had.  At  this  time  there  is  on  my  papers  an  infinity  of  opti- 
cal investigations :  also  a  plan  of  an  eye-piece  with  a  concave 
lens  to  destroy  certain  aberrations.  On  Aug.  2Oth  I  went  to 
Woodford  to  see  Meosrs  Gilbert's  optical  works.  From  Aug. 
1 3th  I  had  been  preparing  for  the  discussion  of  the  Green- 
wich Solar  Errors,  and  I  had  a  man  at  work  in  my  rooms, 
engaged  on  the  calculation  of  the  Errors.  I  wrote  to  Bouvard 
at  Paris  for  observations  of  the  sun,  but  he  recommended  me 
to  wait  for  the  Tables  which  Bessel  was  preparing.  I  was 
busy  too  about  my  Lectures  :  on  Sept.  2Qth  I  have  a  set  of 
plans  of  printing  presses  from  Hansard  the  printer  (who  in  a 


FROM   B.A.   DEGREE   TO   PLUMIAN   PROFESSORSHIP.       77 


visit  to  Cambridge  had  found  me  making  enquiries  about 
them),  and  I  corresponded  with  Messrs  Gilbert  about  optical 
constructions,  and  with  W.  and  S.  Jones,  Eastons,  and  others 
about  pumps,  hydraulic  rams,  &c.  On  Sept.  25th  occurred 
a  very  magnificent  Aurora  Borealis. 

"  I  do  not  find  when  the  investigation  of  Corrections  of 
Solar  Elements  was  finished,  or  when  my  Extracts  from 
Burckhardt,  Connaissance  des  Temps  1816,  were  made.  But 
these  led  me  to  suspect  an  unknown  inequality  in  the  Sun's 
motion.  On  Sept.  27th  and  28th  I  find  the  first  suspicions  of 
an  inequality  depending  on  8  x  mean  longitude  of  Venus  — 
13  x  mean  longitude  of  Earth.  The  thing  appeared  so 
promising  that  I  commenced  the  investigation  of  the  pertur- 
bation related  to  this  term,  and  continued  it  (a  very  laborious 
work)  as  fast  as  I  was  able,  though  with  various  interruptions, 
which  in  fact  were  necessary  to  keep  up  my  spirits.  On 
Oct.  3<Dth  I  went  to  London  for  the  Board  of  Longitude 
meeting.  Here  I  exhibited  the  results  of  my  Sun  investiga- 
tions, and  urged  the  correction  of  the  elements  used  in  the 
Nautical  Almanac.  Dr  Young  objected,  and  proposed  that 
Bouvard  should  be  consulted.  Professor  Woodhouse,  the 
Plumian  Professor,  was  present,  and  behaved  so  captiously 
that  some  members  met  afterwards  to  consider  how  order 
could  be  maintained.  I  believe  it  was  during  this  visit  to 
London  that  I  took  measures  of  Hammersmith  Suspension 
Bridge  for  an  intended  Lecture-model.  Frequently,  but  not 
always,  when  in  London,  I  resided  at  the  house  of  Mr  Sheep- 
shanks and  his  sister  Miss  Sheepshanks,  30  Woburn  Place. 
My  quires,  at  this  time,  abound  with  suggestions  for  lectures 
and  examinations. 

"  On  some  day  about  the  end  of  November  or  beginning 
of  December  1827,  when  I  was  walking  with  Mr  Peacock 
near  the  outside  gate  of  the  Trinity  Walks,  on  some  mention 
of  Woodhouse,  the  Plumian  Professor,  Mr  Peacock  said  that 
he  was  never  likely  to  rise  into  activity  again  (or  using  some 
expression  importing  mortal  illness).  Instantly  there  had 


78  GEORGE   BIDDELL  AIRY. 

passed  through  my  mind  the  certainty  of  my  succeeding  him, 
the  good  position  in  which  I  stood  towards  the  University, 
the  probability  of  that  position  being  improved  by  improved 
lectures,  &c.,  &c.,  and  J>y  increased  reputation  from  the 
matters  in  which  I  was  now  engaged,  the  power  of  thus 
commanding  an  increase  of  income.  I  should  then  have, 
independent  of  my  Fellowship,  some  competent,  income,  and 
a  house  over  my  head.  I  was  quite  aware  that  some  time 
might  elapse,  but  now  for  the  first  time  I  saw  my  way  clearly. 
The  care  of  the  Observatory  had  been  for  two  or  three  years 
attached  to  the  Plumian  Professorship.  A  Grace  was  imme- 
diately prepared,  entrusting  the  temporary  care  of  the  Obser- 
vatory to  Dr  French,  to  me,  Mr  Catton,  Mr  Sheepshanks, 
and  Mr  King  (afterwards  Master  of  Queens'  College).  On 
Dec.  6th  I  have  a  note  from  Mr  King  about  going  to  the 
Observatory. 

"  On  Dec.  6th  my  Paper  on  corrections  of  the  elements  of 
the  Solar  Tables  was  presented  to  the  Royal  Society.  On 
Dec.  Qth,  at  I  h.  4  m.  a.m.  (Sunday  morning),  I  arrived  at  the 
result  of  my  calculations  of  the  new  inequality.  I  had  gone 
through  some  fluctuations  of  feeling.  Usually  the  important 
part  of  an  inequality  of  this  kind  depends  entirely  on  the 
eccentricities  of  the  orbits,  but  it  so  happened  that  from  the 
positions  of  the  axes  of  the  orbits,  &c.,  these  terms  very 
nearly  destroyed  each  other.  After  this  came  the  considera- 
tion of  inclinations  of  orbits ;  and  here  were  sensible  terms 
which  were  not  destroyed.  Finally  I  arrived  at  the  result 
that  the  inequality  would  be  about  3";  just  such  a  magnitude 
as  was  required.  I  slipped  this  into  Whewell's  door.  This 
is,  to  the  time  of  writing  (1853),  the  last  improvement  of  any 
importance  in  the  Solar  Theory.  Some  little  remaining  work 
went  on  to  Dec.  I4th,  and  then,  being  thoroughly  tired,  I  laid 
by  the  work  for  revision  at  some  future  time.  I  however 
added  a  Postscript  to  my  Royal  Society  Paper  on  Solar 
Errors,  notifying  this  result. 

"  On  Dec.  iQth  I  went  to  Bury.    While  there  I  heard  from 


FROM   B.A.    DEGREE   TO    PLUMIAN    PROFESSORSHIP.       79 

Whewell  that  Woodhouse  was  dead.  I  returned  to  Cam- 
bridge and  immediately  made  known  that  I  was  a  candidate 
for  the  now  vacant  Plumian  Professorship.  Of  miscellaneous 
scientific  business,  I  find  that  on  Oct.  I3th  Professor  Barlow 
of  Woolwich  prepared  a  memorial  to  the  Board  of  Longitude 
concerning  his  fluid  telescope  (which  I  had  seen  at  Woodford), 
which  was  considered  on  Nov.  1st,  and  I  had  some  corre- 
spondence with  him  in  December.  In  June  and  August  my 
Trigonometry  was  printing. 

"On  Jan.  5th,  1828,  I  came  from  London.  It  seems  that 
I  had  been  speculating  truly  '  without  book '  on  perturba- 
tions of  planetary  elements,  for  on  Jan.  i/th  and  i8th  I  wrote 
a  Paper  on  a  supposed  error  of  Laplace,  and  just  at  the  end 
I  discovered  that  he  was  quite  right :  I  folded  up  the  Paper 
and  marked  it  'A  Lesson/  I  set  two  papers  of  questions 
for  Smith's  Prizes  (there  being  a  deficiency  of  one  Examiner, 
viz.  the  Plumian  Professor). 

"Before  the  beginning  of  1828  Whewell  and  I  had  deter- 
mined on  repeating  the  Dolcoath  experiments.  On  Jan.  8th 
I  have  a  letter  from  Davies  Gilbert  (then  President  of  the 
Royal  Society)  congratulating  me  upon  the  Solar  Theory, 
and  alluding  to  our  intended  summer's  visit  to  Cornwall. 
We  had  somehow  applied  to  the  Board  of  Longitude  for 
pendulums,  but  Dr  Young  wished  to  delay  them,  having  with 
Capt.  Basil  Hall  concocted  a  scheme  for  making  Lieut. 
Foster  do  all  the  work :  Whewell  and  I  were  indignant  at 
this,  and  no  more  was  said  about  it.  On  Jan.  24th  Dr  Young, 
in  giving  notice  of  the  Board  of  Longitude  meeting,  informs 
me  that  the  clocks  and  pendulums  are  ready. 

"  I  had  made  known  that  I  was  a  candidate  for  the 
Plumian  Professorship,  and  nobody  thought  it  worth  while 
to  oppose  me.  One  person  at  least  (Earnshaw)  had  intended 
to  compete,  but  he  called  on  me  to  make  certain  that  I  was  a 
candidate,  and  immediately  withdrew.  I  went  on  in  quality 
of  Syndic  for  the  care  of  the  Observatory,  ingrafting  myself 
into  it.  But  meantime  I  told  everybody  that  the  salary 


80  GEORGE   BIDDELL   AIRY. 

(about  ^"300)  was  not  sufficient  for  me ;  and  on  Jan.  2Oth  I 
drafted  a  manifesto  or  application  to  the  University  for  an 
increase  of  salary.  The  day  of  election  to  the  Professorship 
was  Feb.  6th.  As  I  was  officially  (as  Lucasian  Professor)  an 
elector,  I  was  present,  and  T  explained  to  the  electors  that  I 
could  not  undertake  the  responsibility  of  the  Observatory 
without  augmentation  of  income,  and  that  I  requested  their 
express  sanction  to  my  application  to  the  University  for  that 
purpose.  They  agreed  to  this  generally,  and  I  was  elected. 
I  went  to  London  immediately  to  attend  a  meeting  of  the 
Board  of  Longitude  and  returned  on  Feb.  8th.  On  Feb.  I5th 
I  began  my  Lectures  (which,  this  year,  included  Mechanics, 
Optics,  Pneumatics,  and  Hydrostatics)  in  the  room  below  the 
University  Library.  The  number  of  names  was  26.  The 
Lectures  terminated  on  Mar.  22nd. 

"On  Feb.  25th  I  received  from  Mr  Pond  information  on 
the  emoluments  at  Greenwich  Observatory.  I  drew  up  a 
second  manifesto,  and  on  Feb.  26th  I  wrote  and  signed  a 
formal  copy  for  the  Plumian  electors.  On  Feb.  27th  I  met 
them  at  Caius  Lodge  (the  Master,  Dr  Davy,  being  Vice- 
Chancellor).  I  read  my  Paper,  which  was  approved,  and 
their  sanction  was  given  in  the  form  of  a  request  to  the  Vice- 
Chancellor  to  permit  the  paper  to  be  printed  and  circulated. 
My  paper,  with  this  request  at  the  head,  was  immediately 
printed,  and  a  copy  was  sent  to  every  resident  M.A.  (more 
than  200  went  out  in  one  day).  The  statement  and  composi- 
tion of  the  paper  were  generally  approved,  but  the  University 
had  never  before  been  taken  by  storm  in  such  a  manner,  and 
there  was  some  commotion  about  it.  I  believe  that  very  few 
persons  would  have  taken  the  same  step.  Mr  Sheepshanks 
wrote  to  me  on  Mar.  7th,  intimating  that  it  was  desperate. 
I  had  no  doubt  of  success.  Whewell  told  me  that  some 
people  accused  me  of  bad  faith,  in  omitting  allusion  to  the 
£100  a  year  received  as  Member  of  the  Board  of  Longitude, 
and  to  the  profits  of  Lectures.  I  wrote  him  a  note,  telling 
him  that  I  had  most  certain  information  of  the  intention  to 


FROM    B.A.   DEGREE   TO    PLUMIAN    PROFESSORSHIP.       8 1 

dissolve  the  Board  of  Longitude  (which  was  done  in  less  than 
six  months),  and  that  by  two  years'  Lectures  I  had  gained 
£4$  (the  expenses  being  £200,  receipts  £245).  This  letter 
was  sent  to  the  complaining  people,  and  no  more  was  said. 
By  the  activity  of  Sheepshanks  and  the  kindness  of  Dr  Davy 
the  business  gradually  grew  into  shape,  and  on  Mar.  2ist  a 
Grace  passed  the  Senate  for  appointing  a  Syndicate  to  con- 
sider of  augmentation.  Sheepshanks  was  one  of  the  Syndi- 
cate, and  was  understood  to  represent,  in  some  measure,  my 
interests.  The  progress  of  the  Syndicate  however  was  by  no 
means  a  straightforward  one.  Members  of  the  Senate  soon 
began  to  remark  that  before  giving  anything  they  ought  to 
know  the  amount  of  the  University  revenue,  and  another 
Syndicate  was  then  appointed  to  enquire  and  report  upon  it. 
It  was  more  than  a  year  before  my  Syndicate  could  make 
their  recommendation  :  however,  in  fact,  I  lost  nothing  by 
that  delay,  as  I  was  rising  in  the  estimation  of  the  University. 
"The  Observatory  house  was  furnished,  partly  from  Wood- 
house's  sale,  and  partly  from  new  furniture.  My  mother  and 
sister  came  to  live  with  me  there.  On  Mar.  I5th  1828  I 
began  the  Observatory  Journal ;  on  Mar.  2/th  I  slept  at 
the  Observatory  for  the  first  time,  and  on  Apr.  i5th  I  came 
to  reside  there  permanently,  and  gave  up  my  college  rooms." 


A.  B. 


CHAPTER    IV. 

AT    CAMBRIDGE    OBSERVATORY.       FROM     HIS    TAKING 
CHARGE  OF  THE  CAMBRIDGE  OBSERVATORY  TO  HIS 

RESIDENCE    AT     GREENWICH     OBSERVATORY     AS     AS- 

TRONOMER  ROYAL. 

FROM  MARCH  ISTH  1828  TO  JAN.  IST  1836. 

1828 

"  I  attended  a  meeting  of  the  Board  of  Longitude  on  Apr. 
3rd.  And  again  on  June  4th ;  this  was  the  last  meeting : 
Sheepshanks  had  previously  given  me  private  information  of 
the  certainty  of  its  dissolution. — On  Apr.  4th  I  visited  Mr 
Herschel  at  Slough,  where  one  evening  I  saw  Saturn  with 
his  2O-foot  telescope,  the  best  view  of  it  that  I  have  ever 
had. — In  June  I  attended  the  Greenwich  Observatory  Visi- 
tation.— Before  my  election  (as  Plumian  Professor)  there  are 
various  schemes  on  my  quires  for  computation  of  transit 
corrections,  &c.  After  Apr.  I5th  there  are  corrections  for 
deficient  wires,  inequality  of  pivots,  &c.  And  I  began  a 
book  of  proposed  regulations  for  observations.  In  this  are 
plans  for  groups  of  stars  for  R.A.  (the  Transit  Instrument 
being  the  only  one  finished):  order  of  preference  of  classes  of 
observations:  no  reductions  to  be  made  after  dinner,  or  on 
Sunday :  no  loose  papers :  observations  to  be  stopped  if 
reductions  are  two  months  in  arrear:  stars  selected  for 
parallax. — The  reduction  of  transits  begins  on  Apr.  I5th. 
On  May  I5th  Mr  Pond  sent  me  some  moon-transits  to  aid  in 
determining  my  longitude. — Dr  Young,  in  a  letter  to  me  of 


AT   CAMBRIDGE   OBSERVATORY.  83 

May  /th,  enquires  whether  I  will  accept  a  free  admission  to 
the  Royal  Society,  which  I  declined.  On  May  pth  I  was 
elected  to  the  Astronomical  Society. — Towards  the  end  of 
the  year  I  observed  Encke's  Comet:  and  determined  the 
latitude  of  the  Observatory  with  Sheepshanks's  repeating 
circle. — On  my  papers  I  find  a  sketch  of  an  Article  on  the 
Figure  of  the  Earth  for  the  Encyclopaedia  Metropolitana. 

"As  early  as  Feb.  23rd  I  had  been  in  correspondence 
with  T.  Jones,  the  instrument-maker,  about  pendulums  for  a 
repetition  of  the  Dolcoath  Experiments.  Invitations  had 
been  received,  and  everything  was  arranged  with  Whewell. 
Sheepshanks,  my  brother,  and  Mr  Jackson  of  Ipswich  (Caius 
Coll.)  were  to  go.  and  we  were  subsequently  joined  by 
Sedgwick,  and  Lodge  (Magdalene  Coll.).  On  July  3rd  Sheep- 
shanks and  I  started  by  Salisbury,  taking  Sherborne  on  our 
way  to  look  at  the  church,  which  had  alarmed  the  people  by 
signs  of  a  crack,  and  arrived  at  Camborne  on  July  8th.  On 
the  I4th  we  set  up  the  pendulums,  and  at  once  commenced 
observations,  our  plan  being,  to  have  no  intermission  in  the 
pendulum  observations,  so  that  as  soon  as  the  arc  became  too 
small  a  fresh  series  was  started.  On  July  2Qth  we  raised  the 
instruments,  and  Sheepshanks,  who  managed  much  of  the 
upper  operations,  both  astronomical  and  of  pendulums, 
mounted  the  pendulums  together  in  his  observatory.  We 
went  on  with  our  calculations,  and  on  August  8th,  on  return- 
ing from  a  visit  to  John  Williams  at  Barncoose,  we  heard  that 
there  was  a  *  run '  in  Dolcoath,  that  is  a  sinking  of  the  whole 
mass  of  rock  where  it  had  been  set  free  by  the  mine  excava- 
tions: probably  only  a  few  inches,  but  enough  to  break  the 
rock  much  and  to  stop  the  pumps.  On  Aug.  loth  the  calcu- 
lations of  our  observations  shewed  that  there  was  something 
wrong,  and  on  the  I3th  I  perceived  an  anomaly  in  the 
form  of  the  knife  edge  of  one  pendulum,  and  of  its  agate 
planes,  and  suggested  cautions  for  repeating  the  observations. 
We  determined  at  once  to  repeat  them  :  and  as  the  water 
was  rising  in  the  mine  there  was  no  time  to  be  lost.  We 

6—2 


84  GEORGE  BIDDELL  AIRY. 

again  sent  the  instruments  down,  and  made  observations  on 
the  1 6th,  1 7th  and  i8th.  On  the  igth  I  sent  the  instruments 
up,  for  the  water  was  near  our  station,  and  Sedgwick,  Whewell, 
and  I  went  on  a  geological  expedition  to  the  Lizard.  On 
our  return  we  met  Sheepshanks  and  the  others,  and  found 
the  results  of  the  last  observations  unsatisfactory.  The 
results  of  comparing  the  pendulums  were  discordant,  and  the 
knife  edge  of  the  faulty  pendulum  had  very  sensibly  altered. 
We  now  gave  up  observations,  with  the  feeling  that  our 
time  had  been  totally  lost,  mainly  through  the  fault  of  the 
maker  of  the  pendulum  (T.  Jones).  On  the  28th  we  made 
an  expedition  to  Penzance  and  other  places,  and  arrived  at 
Cambridge  on  the  i/th  of  September. 

"  In  the  course  of  the  work  at  Dolcoath  we  made  various 
expeditions  as  opportunity  offered.  Thus  we  walked  to 
Carn  Brea  and  witnessed  the  wrestling,  the  common  game 
of  the  country.  On  another  occasion  Sedgwick,  Whewell, 
and  I  had  a  capital  geological  expedition  to  Trewavas  Head 
to  examine  granite  veins.  We  visited  at  Pendarves  and 
Trevince,  and  made  the  expedition  to  the  Lizard  already 
referred  to,  and  saw  many  of  the  sights  in  the  neighbourhood. 
After  visiting  Penzance  on  the  conclusion  of  our  work  we 
saw  Cape  Cornwall  (where  Whewell  overturned  me  in  a  gig), 
and  returned  homewards  by  way  of  Truro,  Plymouth  (where 
we  saw  the  watering-place  and  breakwater:  also  the  Dock- 
yard, and  descended  in  one  of  the  working  diving-bells), 
Exeter,  Salisbury,  and  Portsmouth.  In  returning  from 
Camborne  in  1826  I  lost  the  principal  of  our  papers.  It 
was  an  odd  thing  that,  in  going  through  Exeter  on  our  way 
to  Camborne  in  1828,  I  found  them  complete  at  Exeter, 
identified  to  the  custodian  by  the  dropping  out  of  a  letter 
with  my  address. 

"  On  my  return  to  Cambridge  I  was  immediately  im- 
mersed in  the  work  of  the  Observatory.  The  only  instru- 
ment then  mounted  at  the  Observatory  was  the  Transit.  I 
had  no  Assistant  whatever. — A  Mr  Galbraith  of  Edinburgh 


AT  CAMBRIDGE  OBSERVATORY.  85 

had  questioned  something  in  one  of  my  Papers  about  the 
Figure  of  the  Earth.  I  drew  up  a  rather  formal  answer  to  it: 
Whewell  saw  my  draft  and  drew  up  a  much  more  pithy  one, 
which  I  adopted  and  sent  to  the  Philosophical  Magazine. — 
For  comparing  our  clocks  at  the  upper  and  lower  stations  of 
Dolcoath  we  had  borrowed  from  the  Royal  Observatory, 
Greenwich,  six  good  pocket  chronometers :  they  were  still  in 
the  care  of  Mr  Sheepshanks.  I  arranged  with  him  that  they 
should  be  sent  backwards  and  forwards  a  few  times  for 
determining  the  longitude  of  Cambridge  Observatory.  This 
was  done  on  Oct.  2ist,  22nd,  23rd:  the  result  was  23S*54,  and 
this  has  been  used  to  the  present  time  (1853).  It  evinced 
an  error  in  the  Trigonometrical  Survey,  the  origin  of  which 
was  found,  I  think,  afterwards  (Dr  Pearson  in  a  letter  of  Dec. 
1 7th  spoke  of  the  mistake  of  a  may-pole  for  a  signal-staff). 
I  drew  up  a  Paper  on  this,  and  gave  it  to  the  Cambridge 
Philosophical  Society  on  Nov.  24th.  (My  only  academical 
Paper  this  year.) — I  had  several  letters  from  Dr  Young, 
partly  supplying  me  with  calculations  that  I  wanted,  partly 
on  reform  or  extension  of  the  Nautical  Almanac  (which  Dr 
Young  resisted  as  much  as  possible).  He  considered  me 
very  unfairly  treated  in  the  dissolution  of  the  Board  of 
Longitude :  Professor  Lax  wished  me  to  join  in  some  effort 
for  its  restoration,  but  I  declined. 

"  As  my  reduction  of  observations  was  kept  quite  close,  I 
now  began  to  think  of  printing.  In  regard  to  the  form  I 
determined  to  adopt  a  plan  totally  different  from  that  of  any 
other  observations  which  I  had  seen.  The  results  were  to  be 
the  important  things :  I  was  desirous  of  suppressing  the 
separate  wires  of  transits.  But  upon  consulting  Herschel 
and  other  persons  they  would  not  agree  to  it,  and  I  assented 
to  keeping  them.  I  applied  to  the  Press  Syndicate  to  print 
the  work,  and  on  Nov.  loth  at  the  request  of  T.  Musgrave 
(afterwards  Archbishop  of  York)  I  sent  a  specimen  of  my 
MS.:  on  Nov.  nth  they  granted  250  copies,  and  the  printing 
soon  commenced." 


86  GEORGE   BIDDELL   AIRY. 


1829 

"  During  a  winter  holiday  at  Playford  I  wrote  out  some 
investigations  about  the  'orbits  0T  comets,  and  on  Jan.  23rd 
1829  I  returned  to  Cambridge.  The  Smith's  Prize  Exami- 
nation soon  followed,  in  which  I  set  a  Paper  of  questions  as 
usual.  On  Feb.  i8th  I  made  notes  on  Liesganig's  geodetic 
work  at  the  British  Museum. 

"  I  was  naturally  anxious  now  about  the  settlement  of  my 
salary  and  of  the  Observatory  establishment.  I  do  not 
know  when  the  Syndicate  made  their  Report,  but  it  must 
have  been  in  the  last  term  of  1828.  It  recommended  that 
the  salary  should  be  annually  made  up  (by  Grace)  to  £500 : 
that  an  Assistant  should  be  appointed  with  the  assent  of  the 
Vice-Chancellor-  and  dismissable  by  the  Plumian  Professor: 
and  that  a  Visiting  Syndicate  should  be  appointed,  partly 
official  and  partly  of  persons  to  be  named  every  year  by 
Grace.  The  Grace  for  adopting  this  Report  was  to  be 
offered  to  the  Senate  on  Feb.  27th.  The  passing  of  the 
Grace  was  exposed  to  two  considerable  perils.  First,  I 
found  out  (just  in  time)  that  a  Senior  Fellow  of  Trinity 
(G.  A.  Browne)  was  determined  to  oppose  the  whole,  on  ac- 
count of  the  insignificant  clause  regarding  dismissal  of  Assist- 
ants, which  he  regarded  as  tyrannical.  I  at  once  undertook 
that  that  clause  should  be  rejected.  Secondly,  by  the  absurd 
constitution  of  the  '  Caput '  at  Cambridge,  a  single  M.  A.  had 
the  power  of  stopping  any  business  whatever,  and  an  M.A. 
actually  came  to  the  Senate  House  with  the  intention  of 
throwing  out  all  the  Graces  on  various  business  that  day 
presented  to  the  Senate.  Luckily  he  mistook  the  hour,  and 
came  at  1 1  instead  of  10,  and  found  that  all  were  dispatched. 
The  important  parts  of  the  Grace  passed  without  any  opposi- 
tion :  but  I  mustered  some  friends  who  negatived  that  part 
which  had  alarmed  G.  A.  Browne,  and  it  was  corrected  to  his 
satisfaction  by  a  new  Grace  on  Mar.  i8th.  I  was  now  almost 


AT   CAMBRIDGE   OBSERVATORY.  87 

set  at  rest  on  one  of  the  great  objects  of  my  life:  but  not 
quite.  I  did  not  regard,  and  I  determined  not  to  regard,  the 
addition  to  my  salary  as  absolutely  certain  until  a  payment 
had  been  actually  made  to  me  :  and  I  carefully  abstained, 
for  the  present,  from  taking  any  steps  based  upon  it.  I  found 
for  Assistant  at  the  Observatory  an  old  Lieutenant  of  the 
Royal  Navy,  Mr  Baldrey,  who  came  on  Mar.  16. 

"  On  May  4th  I  began  lectures :  there  were  32  names. 
The  Lectures  were  improving,  especially  in  the  optical  part. 
I  do  not  find  note  of  the  day  of  termination. — I  do  not  know 
the  actual  day  of  publication  of  my  first  small  volume  of 
Cambridge  Observations,  1828,  and  of  circulation.  The  date 
of  the  preface  is  Apr.  2/th  1829.  I  have  letters  of  approval 
of  it  from  Davies  Gilbert,  Rigaud,  and  Lax.  The  system 
which  I  endeavoured  to  introduce  into  printed  astronomical 
observations  was  partially  introduced  into  this  volume,  and 
was  steadily  improved  in  subsequent  volumes.  I  think  that  I 
am  justified,  by  letters  and  other  remarks,  in  believing  that 
this  introduction  of  an  orderly  system  of  exhibition,  not 
merely  of  observations  but  of  the  steps  for  bringing  them  to 
a  practical  result — quite  a  novelty  in  astronomical  publica- 
tions— had  a  markedly  good  effect  on  European  astronomy 
in  general. — In  Feb.  and  March  I  have  letters  from  Young 
about  the  Nautical  Almanac :  he  was  unwilling  to  make  any 
great  change,  but  glad  to  receive  any  small  assistance.  South, 
who  had  been  keeping  up  a  series  of  attacks  on  Young,  wrote 
to  me  to  enquire  how  I  stood  in  engagements  of  assistance  to 
Young :  I  replied  that  I  should  assist  Young  whenever  he 
asked  me,  and  that  I  disapproved  of  South's  course. — The 
date  of  the  first  visitation  of  the  (Cambridge)  Observatory 
must  have  been  near  May  nth:  I  invited  South  and  Baily 
to  my  house ;  South  and  I  were  very  near  quarrelling  about 
the  treatment  of  Young. — In  a  few  days  after  Dr  Young 
died  :  I  applied  to  Lord  Melville  for  the  superintendence  of 
the  Nautical  Almanac:  Mr  Croker  replied  that  it  devolved 
legally  upon  the  Astronomer  Royal,  and  on  May  3<Dth  Pond 


88  GEORGE  BIDDELL  AIRY. 

wrote  to  ask  my  assistance  when  I  could  give  any.  On  June 
6th  I  was  invited  to  the  Greenwich  Visitation,  to  which  I 
believe  I  went  on  the  loth. 

"  I  had  long  desired  to  see  Switzerland,  and  I  wished  now 
to  see  some  of  the  Continental /Observatories.  I  was  there- 
fore glad  to  arrange  with  Mr  Lodge,  of  Magdalene  College 
(perhaps  10  years  senior  to  myself),  to  make  a  little  tour. 
Capt.  W.  H.  Smyth  and  others  gave  me  introductions.  I  met 
Lodge  in  London,  and  we  started  for  Calais  on  July  2;th 
1829.  We  visited  a  number  of  towns  in  Belgium  (at  Brussels 
I  saw  the  beginning  of  the  Observatory  with  Quetelet),  and 
passed  by  Cologne,  Frankfort,  Fribourg,  and  Basle  to  Zurich. 
Thus  far  we  had  travelled  by  diligence  or  posting :  we  now 
procured  a  guide,  and  travelled  generally  on  foot.  From  the 
1 3th  to  the  3  ist  August  we  travelled  diligently  through  the 
well-known  mountainous  parts  of  Switzerland  and  arrived  at 
Geneva  on  the  3ist  August.  Here  I  saw  M.  Gautier,  M. 
Gambard,  and  the  beginning  of  the  Observatory.  Mr  Lodge 
was  now  compelled  to  return  to  Cambridge,  and  I  proceeded 
alone  by  Chambery  to  Turin,  where  I  made  the  acquaintance 
of  M.  Plana  and  saw  the  Observatory.  I  then  made  a  tour 
through  north  Italy,  looking  over  the  Observatories  at  Milan, 
Padua,  Bologna,  and  Florence.  At  Leghorn  I  took  a  passage 
for  Marseille  in  a  xebeque,  but  after  sailing  for  three  days 
the  weather  proved  very  unfavourable,  and  I  landed  at  Spezia 
and  proceeded  by  Genoa  and  the  Cornici  Road  to  Marseille. 
At  Marseille  I  saw  M.  Gambart  and  the  Observatory,  and 
passed  by  Avignon,  Lyons,  and  Nevers  to  Orleans,  where  I 
visited  my  old  host  M.  Legarde.  Thence  by  Paris,  Beauvais, 
and  Calais  to  London  and  Cambridge,  where  I  arrived  on 
the  30th  October.  I  had  started  with  more  than  £140  and 
returned  with  2s.  6d.  The  expedition  was  in  many  ways 
invaluable  to  me. 

"  On  my  return  I  found  various  letters  from  scientific 
men  :  some  approving  of  my  method  for  the  mass  of  the 
Moon  :  some  approving  highly  of  my  printed  observations, 


AT   CAMBRIDGE   OBSERVATORY.  89 

especially  D.  Gilbert,  who  informed  me  that  they  had  pro- 
duced good  effect  (I  believe  at  Greenwich),  and  Herschel. — 
On  Nov.  1 3th  I  gave  the  Royal  Astronomical  Society  a 
Paper  about  deducing  the  mass  of  the  Moon  from  observa- 
tions of  Venus :  on  Nov.  i6th  a  Paper  to  the  Cambridge 
Philosophical  Society  on  a  correction  to  the  length  of  a  ball- 
pendulum  :  and  on  Dec.  I4th  a  Paper  on  certain  conditions 
under  which  perpetual  motion  is  possible. — The  engravings 
for  my  Figure  of  the  Earth  in  the  Encyclopaedia  Metropoli- 
tana  were  dispatched  at  the  end  of  the  year.  Some  of  the 
Paper  (perhaps  much)  was  written  after  my  return  from  the 
Continent. — I  began,  but  never  finished,  a  Paper  on  the  form 
of  the  Earth  supposed  to  be  projecting  at  middle  latitudes. 
In  this  I  refer  to  the  printed  Paper  which  Nicollet  gave  me  at 
Paris.  I  believe  that  the  investigations  for  my  Paper  in  the 
Encyclopaedia  Metropolitana  led  me  to  think  the  supposition 
unnecessary. — On  Nov.  6th  I  was  elected  member  of  the 
Geological  Society. 

"On  Nov.  1 6th  1829  notice  was  given  of  a  Grace  to 
authorize  payment  to  me  of  £157.  gs.  id.,  in  conformity  with 
the  regulations  adopted  on  Feb.  27th,  and  on  Nov.  i8th  the 
Grace  passed  the  Senate.  On  Nov.  I9th  the  Vice-Chancellor 
wrote  me  a  note  enclosing  the  cheque.  On  Nov.  23rd  (prac- 
tically the  first  day  on  which  I  could  go)  I  went  to  London 
and  travelled  to  Edensor,  where  I  arrived  on  the  26th.  Here 
I  found  Richarda  Smith,  proposed  to  her,  and  was  accepted. 
I  stayed  there  a  few  days,  and  returned  to  Cambridge." 


1830 

"On  Jan.  25th  1830  the  Smith's  Prize  Paper  was  prepared. 
I  was  (with  my  Assistant,  Mr  Baldrey)  vigorously  working 
the  Transit  Instrument  and  its  reductions,  and  gradually 
forming  a  course  of  proceeding  which  has  had  a  good  effect 
on  European  Astronomy.  And  I  was  preparing  for  my 
marriage. 


GEORGE   BIDDELL  AIRY. 


"On  Mar.  nth  I  started  with  my  sister  to  London,  and 
arrived  at  Edensor  on  the  afternoon  of  the  I4th.  On  the 
1  7th  I  started  alone  for  Manchester  and  Liverpool.  Through 
Mr  Mason,  a  cotton-spinner  at  Calver,  near  Edensor,  I  had 
become  acquainted  with  Mr  Johft  Kennedy  of  Manchester, 
and  I  had  since  1824  been  acquainted  with  Dr  Traill  of 
Liverpool.  Amongst  other  things,  I  saw  the  works  of  the 
Manchester  and  Liverpool  Railway,  then  advancing  and 
exciting  great  interest,  and  saw  George  Stephenson  and  his 
son.  On  Mar.  24th  I  was  married  to  Richarda  Smith  by  her 
father  in  Edensor.  We  stopped  at  Edensor  till  Apr.  1st,  and 
then  started  in  chaises  by  way  of  Newark  and  Kettering 
(where  we  were  in  danger  of  being  stopped  by  the  snow),  and 
arrived  at  Cambridge  on  Apr.  3rd. 

"  I  was  now  busy  in  preparing  for  lectures,  especially  the 
part  of  the  optical  lectures  which  related  to  the  theory  of 
interferences  and  polarization.  I  think  it  was  now  that  my 
wife  drew  some  of  my  lecture  pictures,  exhibiting  interference 
phenomena.  My  lectures  began  on  Apr.  26th  and  finished 
on  May  24th.  The  number  of  names  was  50-  They  were 
considered  an  excellent  course  of  lectures. 

"  May  Qth  is  the  date  of  my  Preface  to  the  1829  Observa- 
tions :  all  was  then  printed.  Apparently  I  did  not  go  to  the 
Visitation  of  the  Greenwich  Observatory  this  year.  —  I  was  at 
this  time  pressing  Tulley,  the  optician,  about  an  object-glass 
for  the  Mural  Circle.  —  A  new  edition  of  my  '  Tracts  '  was 
wanted,  and  I  prepared  to  add  a  Tract  on  the  Undulatory 
Theory  of  Light  in  its  utmost  extent.  The  Syndicate  of  the 
University  Press  intimated  through  Dr  Turton  that  they 
could  not  assist  me  (regarding  the  book  as  a  second  edition). 
On  July  loth  I  have  some  negociation  about  it  with  Deighton 
the  bookseller.  —  On  May  i8th  I  have  a  note  from  Whewell 
about  a  number  of  crystals  of  plagiedral  quartz,  in  which  he 
was  to  observe  the  crystalline  indication,  and  I  the  optical 
phenomena.  —  The  Report  of  the  Syndicate  for  visiting  the 
Observatory  is  dated  June  i8th  :  it  is  highly  laudatory.  —  The 


AT   CAMBRIDGE  OBSERVATORY.  91 

Proctor  (Barnard  of  King's  College)  requested  me  to  name 
the  Moderator  for  the  next  B.A.  Examination :  I  named  Mr 
Challis. 

"  On  June  I4th  my  wife  and  I  went,  in  company  with  Pro- 
fessor and  Mrs  Henslow,  to  London  and  Oxford ;  at  Oxford 
we  were  received  in  Christchurch  College  by  Dr  and  Mrs 
Buckland.  My  wife  and  I  then  went  to  Bedford  to  visit 
Capt.  and  Mrs  Smyth,  and  returned  to  Cambridge  on  the 
23rd.  On  July  5th  we  went  on  a  visit  to  my  mother  and 
uncle  at  Playford.  While  there  I  took  a  drive  with  my  uncle 
into  some  parts  near  the  valley  of  the  Gipping,  in  which  I 
thought  that  the  extent  of  the  chalk  was  inadequately 
exhibited  on  Greenough's  map,  and  communicated  my  re- 
marks to  Buckland. 

"  I  find  letters  from  Dr  Robinson  and  Col.  Colby  about 
determining  longitudes  of  certain  observatories  by  fire  signals  : 
I  proposed  chronometers  as  preferable.  Also  from  Herschel, 
approving  of  my  second  volume  of  observations :  and  from 
F.  Baily,  disclaiming  the  origination  of  the  attack  on  the  old 
Nautical  Almanac  (with  which  I  suppose  I  had  reproached 
him).  On  July  3Oth  I  received  a  summons  from  South  to  a 
committee  for  improving  the  Nautical  Almanac ;  and  subse- 
quently a  letter  from  Baily  about  Schumacher's  taking 
offence  at  a  passage  of  mine  in  the  Cambridge  Observations, 
on  the  comparative  merits  of  Ephemerides,  which  I  after-  : 
wards  explained  to  his  satisfaction. 

"  On  Aug.  24th  my  wife  and  I  started  for  Edensor,  and 
after  a  short  stay  there  proceeded  by  Manchester  to  Cumber- 
land, where  we  made  many  excursions.  We  returned  by 
Edensor,  and  reached  Cambridge  on  Oct.  6th,  bringing  my 
wife's  sister  Susanna  on  a  visit.  My  mother  had  determined, 
as  soon  as  my  intention  of  marriage  was  known  to  her,  to 
quit  the  house,  although  always  (even  to  her  death)  enter- 
taining the  most  friendly  feelings  and  fondness  for  my  wife. 
It  was  also  judged  best  by  us  all  that  my  sister  should  not 
reside  with  us  as  a  settled  inhabitant  of  the  house.  They 


92  GEORGE   BIDDELL   AIRY. 

fixed  themselves  therefore  at  Playford  in  the  farm-house  of 
the  Luck's  Farm,  then  in  the  occupation  of  my  uncle  Arthur 
Biddell.  On  Oct.  2ist  I  have  a  letter  from  my  sister  saying 
that  they  were  comfortably  settled  there. 

"  In  this  month  of  October  (principally,  I  believe)  I  made 
some  capital  Experiments  on  Quartz,  which  were  treated 
mathematically  in  a  Paper  communicated  in  the  next  year  to 
the  Cambridge  Philosophical  Society.  In  some  of  these  my 
wife  assisted  me,  and  also  drew  pictures. — On  Nov.  I5th  the 
Grace  for  paying  me  £198.  i$s.  %d.  to  make  my  income  up  to 
£500  passed  the  Senate. — I  made  three  journeys  to  London 
to  attend  committees,  one  a  committee  on  the  Nautical 
Almanac,  and  one  a  Royal  Society  Committee  about  two 
southern  observatories. — On  Dec.  3ist  I  have  a  letter  from 
Maclear  (medical  practitioner  and  astronomer  at  Biggies- 
wade)  about  occultations. — In  this  December  I  had  a  quartz 
object-glass  by  Cauchaix  mounted  by  Dollond,  and  presented 
it  to  the  Observatory. — In  this  December  occurred  the  alarm 
from  agrarian  fires.  There  was  a  very  large  fire  at  Coton, 
about  a  mile  from  the  Observatory.  This  created  the  most 
extraordinary  panic  that  I  ever  saw.  I  do  not  think  it  is 
possible,  without  having  witnessed  it,  to  conceive  the  state  of 
men's  minds.  The  gownsmen  were  all  armed  with  bludgeons, 
and  put  under  a  rude  discipline  for  a  few  days." 


1831 

"  On  Jan.  4th  I  went  with  my  wife,  first  to  Miss  Sheep- 
shanks in  London,  at  30,  Woburn  Place,  and  next  to  the 
house  of  my  wife's  old  friend,  the  Rev.  John  Courtney,  at 
Sanderstead,  near  Croydon.  I  came  to  London  on  one  day 
to  attend  a  meeting  of  the  new  Board  of  Visitors  of  the 
Greenwich  Observatory.  Formerly  the  Board  of  Visitors 
consisted  of  the  Council  of  the  Royal  Society  with  persons 
invited  by  them  (in  which  capacity  I  had  often  attended). 
But  a  reforming  party,  of  which  South,  Babbage,  Baily  and 


AT   CAMBRIDGE   OBSERVATORY.  93 

Beaufort  were  prominent  members,  had  induced  the  Admi- 
ralty to  constitute  a  new  Board,  of  which  the  Plumian  Pro- 
fessor was  a  member.  Mr  Pond,  the  Astronomer  Royal,  was 
in  a  rather  feeble  state,  and  South  seemed  determined  to 
bear  him  down  :  Sheepshanks  and  I  did  our  best  to  support 
him.  (I  have  various  letters  from  Sheepshanks  to  this  pur- 
pose.)— On  Jan.  22nd  we  returned  to  Cambridge,  and  I  set 
an  Examination  Paper  for  Smith's  Prizes  as  usual. — On  Jan. 
30th  I  have  a  letter  from  Herschel  about  improving  the 
arrangement  of  Pond's  Observations.  I  believe  that  much  of 
this  zeal  arose  from  the  example  of  the  Cambridge  Observa- 
tions. 

"On  Feb.  2ist  my  Paper  '  On  the  nature  of  the  light  in 
the  two  rays  of  Quartz'  was  communicated  to  the  Philoso- 
phical Society :  a  capital  piece  of  deductive  optics.  On  Mar. 
2nd  I  went  to  London,  I  suppose  to  attend  the  Board  of 
Visitors  (which  met  frequently,  for  the  proposed  reform  of 
Pond's  Observations,  &c.).  As  I  returned  on  the  outside  of 
the  coach  there  occurred  to  me  a  very  remarkable  deduction 
from  my  ideas  about  the  rays  of  Quartz,  which  I  soon  tried 
with  success,  and  it  is  printed  as  an  Appendix  to  the  Paper 
above  mentioned.  On  Mar.  6th  my  son  George  Richard  was 
born." 

Miscellaneous  matters  in  the  first  half  of  this  year  are  as 
follows : 

"  Faraday  sends  me  a  piece  of  glass  for  Amici  (he  had 
sent  me  a  piece  before). — On  Apr.  9th  I  dispatched  the  Pre- 
face of  my  1830  Observations:  this  implies  that  all  was 
printed. — On  Apr.  i8th  I  began  my  Lectures  and  finished  on 
May  24th.  There  were  49  names.  A  very  good  series  of 
lectures. — I  think  it  was  immediately  after  this,  at  the  Visita- 
tion of  the  Cambridge  Observatory,  that  F.  Baily  and  Lieut. 
Stratford  were  present,  and  that  Sheepshanks  went  to  Thar- 
field  on  the  Royston  Downs  to  fire  powder  signals  to  be  seen 
at  Biggies  wade  (by  Maclear)  and  at  Bedford  (by  Capt.  Smyth) 
as  well  as  by  us  at  Cambridge. — On  May  I4th  I  received 


94  GEORGE   BIDDELL  AIRY. 

£  100  for  my  article  on  the  Figure  of  the  Earth  from  Baldwin 
the  publisher  of  the  Encyclopaedia  Metropolitana. — I  attended 
the  Greenwich  Visitation  on  June  3rd. — On  June  3Oth  the 
Observatory  Syndicate  made  their  report :  satisfactory. 

"On  July  6th  1831  I  started  with  my  wife  and  infant  son 
for  Edensor,  and  went  on  alone  to  Liverpool.  I  left  for 
Dublin  on  the  day  on  which  the  loss  of  the  '  Rothsay  Castle ' 
was  telegraphed,  and  had  a  bad  voyage,  which  made  me  ill 
during  my  whole  absence.  After  a  little  stay  in  Dublin  I 
went  to  Armagh  to  visit  Dr  Robinson,  and  thence  to  Cole- 
raine  and  the  Giant's  Causeway,  returning  by  Belfast  and 
Dublin  to  Edensor.  We  returned  to  Cambridge  on  Sept.  Qth. 

"  Up  to  this  time  the  Observatory  was  furnished  with 
only  one  large  instrument,  namely  the  lo-foot  Transit.  On 
Feb.  24th  of  this  year  I  had  received  from  Thomas  Jones 
(62,  Charing  Cross)  a  sketch  of  the  stone  pier  for  mounting 
the  Equatoreal  which  he  was  commissioned  to  make:  and  the 
pier  was  prepared  in  the  spring  or  summer.  On  Sept.  2Oth 
part  of  the  instrument  was  sent  to  the  Observatory ;  other 
parts  followed,  and  Jones  himself  came  to  mount  it.  On 
Sept.  1 6th  I  received  Simms's  assurance  that  he  was  hasten- 
ing the  Mural  Circle. — In  this  autumn  I  seriously  took  up 
the  recalculation  of  my  Long  Inequality  of  Venus  and  the 
Earth,  and  worked  through  it  independently ;  thus  correcting 
two  errors.  On  Nov.  roth  I  went  to  Slough,  to  put  my 
Paper  in  the  hands  of  Mr  Herschel  for  communication  to  the 
Royal  Society.  The  Paper  was  read  on  Nov.  24th. — This 
was  the  year  of  the  first  Meeting  of  the  British  Association  at 
York.  The  next  year's  meeting  was  to  be  at  Oxford,  and  on 
Oct.  1 7th  I  received  from  the  Rev.  W.  Vernon  Harcourt  an 
invitation  to  supply  a  Report  on  Astronomy,  which  I  under- 
took :  it  employed  me  much  of  the  winter,  and  the  succeeding 
spring  and  summer. — The  second  edition  of  my  Tracts  was 
ready  in  October.  It  contained,  besides  what  was  in  the  first 
edition,  the  Planetary  Theory,  and  the  Undulatory  Theory  of 
Light.  The  Profit  was  £80. — On  Nov.  I4th  I  presented  to 


AT   CAMBRIDGE  OBSERVATORY.  95 

the  Cambridge  Philosophical  Society  a  Paper  '  On  a  remark- 
able modification  of  Newton's  Rings ' :  a  pretty  good  Paper. 
— In  November  the  Copley  Medal  was  awarded  to  me  by  the 
Royal  Society  for  my  advances  in  Optics. — Amongst  miscel- 
laneous matters  I  was  engaged  in  correspondence  with  Col. 
Colby  and  Capt.  Portlock  about  the  Irish  Triangulation  and 
its  calculation.  Also  with  the  Admiralty  on  the  form  of 
publication  of  the  Greenwich  and  Cape  Observations." 


1832 

"  In  January  my  Examination  Paper  for  Smith's  Prizes 
was  prepared  as  usual. — Two  matters  (in  addition  to  the 
daily  routine  of  Observatory  work)  occupied  me  at  the  begin- 
ning of  this  year.  One  was  the  translation  of  Encke's  Paper 
in  successive  numbers  of  the  Astronomische  Nachrichten 
concerning  Encke's  Comet ;  the  University  Press  printed  this 
gratuitously,  and  I  distributed  copies,  partly  by  the  aid  of 
Capt.  Beaufort. — The  other  was  the  Report  on  Astronomy 
for  the  British  Association,  which  required  much  labour. 
My  reading  for  it  was  principally  in  the  University  Library 
(possibly  some  in  London),  but  I  borrowed  some  books  from 
F.  Baily,  and  I  wrote  to  Capt.  Beaufort  about  the  possible 
repetition  of  Lacaille's  Meridian  Arc  at  the  Cape  of  Good 
Hope.  The  Report  appears  to  have  been  finished  on  May 
2nd. — At  this  time  the  Reform  Bill  was  under  discussion, 
and  one  letter  written  by  me  (probably  at  Sheepshanks's 
request)  addressed  I  think  to  Mr  Drummond,  Lord  Althorp's 
secretary,  was  read  in  the  House  of  Commons. 

"  Optics  were  not  neglected.  I  have  some  correspondence 
with  Brewster  and  Faraday.  On  Mar.  5th  I  gave  the  Cam- 
bridge Philosophical  Society  a  Paper  '  On  a  new  Analyzer/ 
and  on  Mar.  ipth.  one  'On  Newton's  Rings  between  two  sub- 
stances of  different  refractive  powers,'  both  Papers  satisfac- 
tory to  myself. — On  the  death  of  Mr  F.  Fallows,  astronomer 
at  the  Cape  of  Good  Hope  Observatory,  the  Admiralty 


96  GEORGE  BIDDELL  AIRY. 

appointed  Mr  Henderson,  an  Edinburgh  lawyer,  who  had 
done  some  little  things  in  astronomical  calculation.  On  Jan. 
loth  I  discussed  with  him  observations  to  be  made,  and  drew 
up  his  Official  Instructions  whigh  were  sent  on  Jan.  i6th. — 
On  Feb.  i6th  Sir  James  South  Writes  that  Encke's  Comet  is 
seen  :  also  that  with  his  1 2-inch  achromatic,  purchased  at 
Paris,  and  which  he  was  preparing  to  mount  equatoreally,  he 
had  seen  the  disk  of  Aldebaran  apparently  bisected  by  the 
Moon's  limb. — Capt.  Beaufort  and  D.  Gilbert  write  in  March 
about  instructions  to  Dunlop,  the  astronomer  at  Paramatta. 
I  sent  a  draft  to  Capt.  Beaufort  on  Apr.  27th. 

"  The  Preface  to  my  1831  Observations  is  dated  Mar.  2Oth. 
The  distribution  of  the  book  would  be  a  few  weeks  later. — 
On  May  7th  I  began  my  Lectures  :  5 1  names :  I  finished  on 
May  29th. — The  mounting  of  the  Equatoreal  was  finished 
some  time  before  the  Syndicate  Visitation  at  the  end  of  May, 
but  Jones's  charge  appeared  to  be  exorbitant :  I  believe  it 
was  paid  at  last,  but  it  was  considered  unfair. — On  June  2nd 
I  went  to  London  :  I  presume  to  the  Greenwich  Visitation. — 
I  went  to  Oxford  to  the  meeting  of  the  British  Association 
(lodging  I  think  with  Prof.  Rigaud  at  the  Observatory)  on 
June  1 6th,  and  read  part  of  my  Report  on  Astronomy  in  the 
Theatre. 

"On  June  26th  I  started  with  my  wife  for  the  Highlands  of 
Scotland.  After  a  short  stay  at  Edensor,  we  went  by  Carlisle 
to  Glasgow,  and  through  the  Lake  District  to  Inverness. 
Thence  by  Auchnanault  to  Balmacarra,  where  we  were 
received  by  Mr  Lillingstone.  After  an  expedition  in  Skye, 
we  returned  to  Balmacarra,  and  passed  on  to  Invermoriston, 
where  we  were  received  by  Grant  of  Glenmoriston.  We  then 
went  to  Fort  William  and  Oban,  and  crossed  over  to  Mull, 
where  we  were  received  by  Maclean  of  Loch  Buy.  We 
returned  to  Oban  and  on  to  Edinburgh,  where  we  made  a 
short  stay.  Then  to  Melrose,  where  we  were  received  by 
Sir  D.  Brewster,  and  by  Edensor  to  Cambridge,  where  we 
arrived  on  Sept.  I7th. 


AT   CAMBRIDGE  OBSERVATORY.  97 

"  I  received  (at  Edinburgh  I  believe)  a  letter  from  Arago, 
writing  for  the  plans  of  our  observing-room  shutters. — Mr 
Vernon  Harcourt  wrote  deprecating  the  tone  of  my  Report 
on  Astronomy  as  related  to  English  Astronomers,  but  I 
refused  to  alter  a  word. —  Sheepshanks  wrote  in  September  in 
great  anxiety  about  the  Cambridge  Circle,  for  which  he 
thought  the  pier  ought  to  be  raised  :  I  would  have  no  such 
thing,  and  arranged  it  much  more  conveniently  by  means  of 
a  pit.  On  Oct.  gth  Simms  says  that  he  will  come  with  the 
circle  immediately,  and  Jones  on  Sept.  29th  says  that  he  will 
make  some  alteration  in  the  equatoreal :  thus  there  was  at 
last  a  prospect  of  furnishing  the  Observatory  properly. — On 
Oct.  9th,  I  have  Encke's  thanks  for  the  translation  of  the 
Comet  Paper. — One  of  the  desiderata  which  I  had  pointed 
out  in  my  Report  on  Astronomy  was  the  determination  of 
the  mass  of  Jupiter  by  elongations  of  the  4th  satellite :  and 
as  the  Equatoreal  of  the  Cambridge  Observatory  was  on  the 
point  of  coming  into  use,  I  determined  to  employ  it  for  this 
purpose.  It  was  necessary  for  the  reduction  of  the  observa- 
tions that  I  should  prepare  Tables  of  the  motion  of  Jupiter's 
4th  Satellite  in  a  form  applicable  to  computations  of  dif- 
ferences of  right-ascension.  The  date  of  my  Tables  is  Oct. 
3rd,  1832. — In  October  the  Observatory  Syndicate  made  their 
Report :  quite  satisfactory. 

"  On  Oct.  2Oth  Sheepshanks  wrote  asking  my  assistance  in 
the  Penny  Cyclopaedia  :  I  did  afterwards  write  *  Gravitation ' 
and  '  Greenwich.' — Capt.  Beaufort  wrote  in  November  to  ask 
my  opinion  on  the  Preface  to  an  edition  of  Groombridge's 
Catalogue  which  had  been  prepared  by  H.  Taylor:  Sheep- 
shanks also  wrote;  he  had  objected  to  it.  This  was  the 
beginning  of  an  affair  which  afterwards  gave  me  great 
labour. — Vernon  Harcourt  writes,  much  offended  at  some 
terms  which  I  had  used  in  reference  to  an  office  in  the  British 
Association. 

"  The  Equatoreal  mounting  which  Troughton  and  Simms 
had  been  preparing  for  Sir  James   South's   large  telescope 
A.  B.  7 


98  GEORGE   BIDDELL  AIRY. 

had  not  entirely  succeeded.  I  have  various  letters  at  this 
time  from  Sheepshanks  and  Simms,  relating  to  the  disposi- 
tion which  Sir  James  South  shewed  to  resist  every  claim  till 
compelled  by  law  to  pay  it. — A  .general  election  of  Members 
of  Parliament  was  now  coming  on :  Mr  Lubbock  was  candi- 
date for  the  University.  On  Nov.  27th  I  had  a  letter  from 
Sedgwick  requesting  me  to  write  a  letter  in  the  newspapers 
in  favour  of  Lubbock;  which  I  did.  On  Dec.  7th  I  have 
notice  of  the  County  voting  at  Newmarket  on  Dec.  i8th  and 
1 9th :  I  walked  there  to  vote  for  Townley ;  he  lost  the 
election  by  two  or  three  votes  in  several  thousands. 

"  The  Mural  Circle  was  now  nearly  ready  in  all  respects, 
and  it  was  known  that  another  Assistant  would  be  required. 
Mr  Richardson  (one  of  the  Assistants  of  Greenwich  Ob- 
servatory) and  Mr  Simms  recommended  to  me  Mr  Glaisher, 
who  was  soon  after  appointed,  and  subsequently  became  an 
Assistant  at  Greenwich. — On  Dec.  24th  I  have  a  letter  from 
Bessel  (the  first  I  believe).  I  think  that  I  had  written  to  him 
about  a  general  reduction  of  the  Greenwich  Planetary  Ob- 
servations, using  his  Tabulae  Regiomontanae  as  basis,  and 
that  this  was  his  reply  approving  of  it. 

1833 

"On  Jan.  4th  1833  my  daughter  Elizabeth  was  born. — I 
prepared  an  examination  paper  for  Smith's  Prizes  as  usual. — 
On  Jan.  5th  I  received  notice  from  Simms  that  he  had 
received  payment  (£1050)  for  the  Mural  Circle  from  the 
Vice-Chancellor.  About  this  time  the  Circle  was  completely 
made  serviceable,  and  I  (with  Mr  Glaisher  as  Assistant)  im- 
mediately began  its  use.  A  puzzling  apparent  defect  in  the 
circle  (exhibiting  itself  by  the  discordance  of  zenith  points 
obtained  by  reflection  observations  on  opposite  sides  of  the 
zenith)  shewed  itself  very  early.  On  Feb.  4th  I  have  letters 
about  it  from  Sheepshanks  and  Simms. — On  Jan.  I7th  I 
received  notice  from  F.  Baily  that  the  Astronomical  Society 
had  awarded  me  their  Medal  for  my  long  inequality  of 


AT   CAMBRIDGE   OBSERVATORY.  99 

Venus  and  the  Earth :  on  Feb.  7th  I  went  to  London,  I 
suppose  to  receive  the  Medal. — I  also  inspected  Sir  J.  South's 
telescope,  then  becoming  a  matter  of  litigation,  and  visited 
Mr  Herschel  at  Slough:  on  Feb.  I2th  I  wrote  to  Sir  J. 
South  about  the  support  of  the  instrument,  hoping  to  remove 
one  of  the  difficulties  in  the  litigation ;  but  it  produced  no 
effect. — Herschel  wrote  to  me,  from  Poisson,  that  Ponte- 
coulant  had  verified  my  Long  Inequality. 

"Mar.  I2th  is  the  date  of  the  Preface  to  my  1832  volume 
of  Observations:  it  was  of  course  distributed  a  few  weeks 
later. — In  my  Report  on  Astronomy  I  had  indicated  the 
Mass  of  Jupiter  as  a  subject  requiring  fresh  investigation. 
During  the  last  winter  I  had  well  employed  the  Equatoreal 
in  observing  elongations  in  R.A.  of  the  4th  Satellite.  To 
make  these  available  it  was  necessary  to  work  up  the  theory 
carefully,  in  which  I  discovered  some  remarkable  errors  of 
Laplace.  Some  of  these,  for  verification,  I  submitted  to  Mr 
Lubbock,  who  entirely  agreed  with  me.  The  date  of  my 
first  calculations  of  the  Mass  of  Jupiter  is  Mar.  1st :  and 
shortly  after  that  I  gave  an  oral  account  of  them  to  the 
Cambridge  Philosophical  Society.  The  date  of  my  Paper  for 
the  Astronomical  Society  is  April  I2th.  The  result  of  my 
investigations  (which  was  subsequently  confirmed  by  Bessel) 
entirely  removed  the  difficulty  among  Astronomers ;  and  the 
mass  which  I  obtained  has  ever  since  been  received  as  the 
true  one. 

"On  Apr.  9th  my  wife's  two  sisters,  Elizabeth  and 
Georgiana  Smith,  came  to  stay  with  me. — On  Apr.  22nd  I 
began  lectures,  and  finished  on  May  2ist:  there  were  54 
names.  During  the  course  of  the  lectures  I  communicated  a 
Paper  to  the  Philosophical  Society  '  On  the  calculation  of 
Newton's  experiments  on  Diffraction.' — I  went  to  London  on 
the  Visitation  of  the  Greenwich  Observatory :  the  dinner  had 
been  much  restricted,  but  was  now  made  more  open. — It  had 
been  arranged  that  the  meeting  of  the  British  Association 
was  to  be  held  this  year  at  Cambridge.  I  invited  Sir  David 

7—2 


100  GEORGE   BIDDELL  AIRY. 

Brewster  and  Mr  Herschel  to  lodge  at  the  Observatory. 
The  meeting  lasted  from  June  24th  to  3Oth.  We  gave  one 
dinner,  but  had  a  breakfast  party  every  day.  I  did  not  enter 
much  into  the  scientific  business  of  the  meeting,  except  that 
I  brought  before  the  Committee  the  expediency  of  reducing 
the  Greenwich  Planetary  Observations  from  1750.  They 
agreed  to  represent  it  to  the  Government,  and  a  deputation 
was  appointed  (I  among  them)  who  were  received  by  Lord 
Althorp  on  July  25th.  On  Aug.  3rd  Herschel  announced  to 
me  that  £500  was  granted. 

"  On  Aug.  7th  I  started  with  my  wife  for  Edensor.  At 
Leicester  we  met  Sedgwick  and  Whewell :  my  wife  went  on 
to  Edensor,  and  I  joined  Sedgwick  and  Whewell  in  a 
geological  expedition  to  Mount  Sorrel  and  various  parts  of 
Charnwood  Forest.  We  were  received  by  Mr  Allsop  of 
Woodlands,  who  proved  an  estimable  acquaintance.  This 
lasted  four  or  five  days,  and  we  then  went  on  to  Edensor. — 
On  Aug.  1 5th  Herschel  wrote  to  me,  communicating  an  offer 
of  the  Duke  of  Northumberland  to  present  to  the  Cambridge 
Observatory  an  object-glass  of  about  12  inches  aperture  by 
Cauchaix.  I  wrote  therefore  to  the  Duke,  accepting  gene- 
rally. The  Duke  wrote  to  me  from  Buxton  on  Aug.  23rd 
(his  letter,  such  was  the  wretched  arrangement  of  postage, 
reaching  Bakewell  and  Edensor  on  the  25th)  and  on  the  26th 
I  drove  before  breakfast  to  Buxton  and  had  an  interview 
with  him.  On  Sept.  ist  the  Duke  wrote,  authorizing  me  to 
mount  the  telescope  entirely,  and  he  subsequently  approved 
of  Cauchaix's  terms  :  there  was  much  correspondence,  but 
on  Dec.  28th  I  instructed  Cauchaix  how  to  send  the  tele- 
scope.— On  our  return  we  paid  a  visit  to  Dr  Davy,  Master 
of  Caius  College,  at  Heacham,  and  reached  Cambridge  on 
Oct.  8th. 

"  Groombridge's  Catalogue,  of  which  the  editing  was  for- 
mally entrusted  to  Mr  Henry  Taylor  (son  of  Taylor  the  first- 
assistant  of  the  Greenwich  Observatory),  had  been  in  some 
measure  referred  to  Sheepshanks:  and  he,  in  investigating 


AT   CAMBRIDGE   OBSERVATORY. 


the  work,  found  reason  for  thinking  the  whole  discreditable. 
About  May  he  first  wrote  to  me  on  his  rising  quarrel  with  H. 
Taylor,  but  on  Sept.  /th  he  found  things  coming  to  a  crisis, 
and  denounced  the  whole.  Capt.  Beaufort  the  Hydro- 
grapher  (in  whose  office  this  matter  rested)  begged  me  with 
Baily  to  decide  upon  it.  We  did  not  at  first  quite  agree  upon 
the  terms  of  investigation  &c.,  but  after  a  time  all  was  settled, 
and  on  Oct.  4th  the  Admiralty  formally  applied,  and  I  for- 
mally7 accepted.  Little  or  nothing  had  been  done  by  Mr 
Baily  and  myself,  when  my  work  was  interrupted  by  illness. 

"  Sheepshanks  had  thought  that  something  might  be  done 
to  advance  the  interests  of  myself  or  the  Observatory  by  the 
favour  of  Lord  Brougham  (then  Lord  Chancellor),  and  had 
urged  me  to  write  an  article  in  the  Penny  Cyclopaedia,  in 
which  Lord  Brougham  took  great  interest.  I  chose  the 
subject  '  Gravitation,'  and  as  I  think  wrote  a  good  deal  of  it 
in  this  Autumn  :  when  it  was  interrupted  by  my  illness. 

"On  Dec.  9th  1833,  having  at  first  intended  to  attend 
the  meeting  of  the  Philosophical  Society  and  then  having 
changed  my  mind,  I  was  engaged  in  the  evening  on  the 
formulae  for  effects  of  small  errors  on  the  computation  of 
the  Solar  Eclipse  of  1833.  A  dizziness  in  my  head  came 
on.  I  left  off  work,  became  worse,  and  went  to  bed,  and  in 
the  night  was  in  high  fever  with  a  fierce  attack  of  scarlet 
fever.  My  wife  was  also  attacked  but  very  slightly.  The 
first  day  of  quitting  my  bedroom  was  Dec.  3ist.  Some- 
where about  the  time  of  my  illness  my  wife's  sister,  Susanna 
Smith,  who  was  much  reduced  in  the  summer,  died  of  con- 
sumption. 

"  Miscellaneous  notes  in  1833  are  as  follows:  Henderson 
(at  the  Cape)  could  not  endure  it  much  longer,  and  on 
Oct.  1  4th  Stratford  writes  that  Maclear  had  just  sailed  to 
take  his  place  :  Henderson  is  candidate  for  the  Edinburgh 
Observatory.  —  Stratford  writes  on  Dec.  2nd  that  the  Madras 
observations  have  come  to  England,  the  first  whose  arrange- 
ment imitates  mine.  —  On  Nov.  3rd  Herschel,  just  going  to 


GEORGE   BIDDELL  AIRY. 


the  Cape,  entrusted  to  me  the  revisal  of  some  proof  sheets,  if 
necessary  :  however  it  was  never  needed.  —  In  November  I 
sat  for  my  portrait  to  a  painter  named  Purdon  (I  think):  he 
came  to  the  house  and  made  a  good  likeness.  A  pencil 
portrait  was  taken  for  a  print-seller  (Mason)  in  Cambridge  : 
it  was  begun  before  my  illness  and  finished  after  it.  —  I 
applied  through  Sheepshanks  for  a  copy  of  Maskelyne's 
Observations,  to  be  used  in  the  Reduction  of  the  Planetary 
Observations  :  and  on  Dec.  24th  (from  my  bedroom)  I  ap- 
plied through  Prof.  Rigaud  to  the  Delegates  of  the  Clarendon 
Press  for  a  copy  of  Bradley's  Observations  for  the  same. 
The  latter  request  was  refused.  In  October  I  applied  to  the 
Syndics  of  the  University  Press  for  printed  forms  for  these 
Reductions  :  the  Syndics  agreed  to  grant  me  12,000  copies. 


1834 

"On  Jan.  nth  1834  I  went  with  my  wife  to  London  for 
the  recruiting  of  my  strength.  We  stayed  at  the  house  of 
our  friend  Miss  Sheepshanks,  and  returned  on  Feb.  I3th.  — 
I  drew  up  a  Paper  of  Questions  for  Smith's  Prizes,  but  left 
the  whole  trouble  of  examination  and  adjudication  to  Pro- 
fessor Miller,  who  at  my  request  acted  for  me.  —  While  I  was 
in  London  I  began  to  look  at  the  papers  relating  to  Groom- 
bridge's  Catalogue  :  and  I  believe  that  it  was  while  in  London 
that  I  agreed  with  Mr  Baily  on  a  Report  condemnatory  of 
H.  Taylor's  edition,  and  sent  the  Report  to  the  Admiralty. 
The  Admiralty  asked  for  further  advice,  and  on  Feb.  28th  I 
replied,  undertaking  to  put  the  Catalogue  in  order.  On  Mar. 
1  7th  Capt.  Beaufort  sent  me  all  the  papers.  Some  time  how- 
ever elapsed  before  I  could  proceed  with  it. 

"  There  was  in  this  spring  a  furious  discussion  about  the 
admission  of  Dissenters  into  the  University  :  I  took  the 
Liberal  side.  On  Apr.  3Oth  there  was  a  letter  of  mine  in 
the  Cambridge  newspaper.  —  On  Apr.  I4th  I  began  lectures, 
and  finished  on  May  2Oth  :  there  were  87  names.  —  My  'Gravi- 


AT   CAMBRIDGE  OBSERVATORY.  IO3 

tation '  was  either  finished  or  so  nearly  finished  that  on  Jan. 
24th  I  had  some  conversation  with  Knight  the  publisher 
about  printing  it.  It  was  printed  in  the  spring,  and  on  Apr. 
27th  Sheepshanks  sent  a  copy  of  it  to  Lord  Brougham.  I 
received  from  Knight  £83.  i?s.  id.  for  this  Paper. — On  May 
loth  I  went  to  London,  I  believe  to  attend  one  of  the  Soirees 
which  the  Duke  of  Sussex  gave  as  President  of  the  Royal 
Society.  The  Duke  invited  me  to  breakfast  privately  with 
him  the  next  morning.  He  then  spoke  to  me,  on  the  part  of 
the  Government,  about  my  taking  the  office  of  Astronomer 
Royal.  On  May  ipth  I  wrote  him  a  semi-official  letter,  to 
which  reference  was  made  in  subsequent  correspondence  on 
that  subject. 

"On  May  I2th  my  son  Arthur  was  born. — In  June  the 
Observatory  Syndicate  made  a  satisfied  Report— On  June 
7th  I  went  to  the  Greenwich  Visitation,  and  again  on  June 
1 4th  I  went  to  London,  I  believe  for  the  purpose  of  trying 
the  mounting  of  South's  telescope,  as  it  had  been  strengthened 
by  Mr  Simms  by  Sheepshanks's  suggestions.  I  was  sub- 
sequently in  correspondence  with  Sheepshanks  on  the  subject 
of  the  Arbitration  on  South's  telescope,  and  my  giving  evi- 
dence on  it.  On  July  29th,  as  I  was  shortly  going  away,  I 
wrote  him  a  Report  on  the  Telescope,  to  be  used  in  case  of 
my  absence.  The  award,  which  was  given  in  December,  was 
entirely  in  favour  of  Simms. — On  July  23rd  I  went  out,  I 
think  to  my  brother's  marriage  at  Ixworth  in  Suffolk. — On 
Aug.  ist  I  started  for  Edensor  and  Cumberland,  with  my 
wife,  sister,  and  three  children :  Georgiana  Smith  joined  us 
at  Edensor.  We  went  by  Otley,  Harrogate,  Ripon,  and 
Stanmoor  to  Keswick,  from  whence  we  made  many  excur- 
sions. On  Aug.  nth  I  went  with  Whewell  to  the  clouds  on 
Skiddaw,  to  try  hygrometers.  Mr  Baily  called  on  his  way  to 
the  British  Association  at  Edinburgh.  On  Sept.  loth  we 
transferred  our  quarters  to  Ambleside,  and  after  various 
excursions  we  returned  to  Edensor  by  Skipton  and  Bolton. 
On  Sept.  ipth  I  went  to  Doncaster  and  Finningley  Park  to 


104  GEORGE   BIDDELL  AIRY. 

see  Mr  Beaumont's  Observatory.  On  Sept.  25th  we  posted 
in  one  day  from  Edensor  to  Cambridge. 

"  On  Aug.  25th  Mr  Spring  Rice  (Lord  Monteagle)  wrote 
to  me  to  enquire  whether  I  would;  accept  the  office  of  Astro- 
nomer Royal  if  it  were  vacant.  'I  replied  (from  Keswick)  on 
Aug.  3Oth,  expressing  my  general  willingness,  stipulating  for 
my  freedom  of  vote,  &c.,  and  referring  to  my  letter  to  the 
Duke  of  Sussex.  On  Oct.  8th  Lord  Auckland,  First  Lord  of 
the  Admiralty,  wrote  :  and  on  Oct.  loth  I  provisionally  ac- 
cepted the  office.  On  Oct.  3<Dth  I  wrote  to  ask  for  leave  to  give 
a  course  of  lectures  at  Cambridge  in  case  that  my  successor 
at  Cambridge  should  find  difficulty  in  doing  it  in  the  first 
year  :  and  to  this  Lord  Auckland  assented  on  Oct.  3ist.  All 
this  arrangement  was  for  a  time  upset  by  the  change  of 
Ministry  which  shortly  followed. 

"Amongst  miscellaneous  matters,  in  March  I  had  some 
correspondence  with  the  Duke  of  Northumberland  about  the 
Cauchaix  Telescope.  In  August  I  had  to  announce  to  him 
that  the  flint-lens  had  been  a  little  shattered  in  Cauchaix's 
shop  and  required  regrinding :  finally  on  Dec.  i/th  I  an- 
nounced its  arrival  at  Cambridge. — In  the  Planetary  Reduc- 
tions. I  find  that  I  employed  one  computer  (Glaisher)  for  34 
weeks. — In  November  the  Lalande  Medal  was  awarded  to  me 
by  the  French  Institut,  and  Mr  Pentland  conveyed  it  to  me 
in  December. — On  March  I4th  I  gave  the  Cambridge  Philo- 
sophical Society  a  Paper,  '  Continuation  of  researches  into 
the  value  of  Jupiter's  Mass.'  On  Apr.  I4th,  'On  the  Lati- 
tude of  Cambridge  Observatory.'  On  June  I3th,  'On  the 
position  of  the  Ecliptic,'  and  '  On  the  Solar  Eclipse  of  1833,' 
to  the  Royal  Astronomical  Society.  On  Nov.  24th,  'On 
Computing  the  Diffraction  of  an  Object  Glass,'  to  the  Cam- 
bridge Society.  And  on  Dec.  3rd,  '  On  the  Calculation  of 
Perturbations,'  to  the  Nautical  Almanac :  this  Paper  was 
written  at  Keswick  between  Aug.  22nd  and  29th. — I  also 
furnished  Mr  Sheepshanks  with  investigations  regarding  the 
form  of  the  pivots  of  the  Cape  Circle. 


AT   CAMBRIDGE  OBSERVATORY.  1 05 

1835 

"On  Jan.  Qth  1835  I  was  elected  correspondent  of  the 
French  Academy;  and  on  Jan.  26th  Mr  Pentland  sent  me 
£12.  6s.,  the  balance  of  the  proceeds  of  the  Lalande  Medal 
Fund. — I  prepared  my  Paper  for  Smith's  Prizes,  and  joined 
in  the  Examination  as  usual. 

"There  had  been  a  very  sudden  change  of  Administra- 
tion, and  Sir  R.  Peel  was  now  Prime  Minister  as  First  Lord 
of  the  Treasury,  and  Lord  Lyndhurst  was  Lord  Chancellor. 
On  Jan.  I9th  I  wrote  to  Lord  Lyndhurst,  asking  him  for  a 
Suffolk  living  for  my  brother  William,  which  he  declined  to 
give,  though  he  remembered  my  application  some  years  later. 
Whether  my  application  led  to  the  favour  which  I  shortly 
received  from  the  Government,  I  do  not  know.  But,  in 
dining  with  the  Duke  of  Sussex  in  the  last  year,  I  had  been 
introduced  to  Sir  R.  Peel,  and  he  had  conversed  with  me  a 
long  time,  and  appeared  to  have  heard  favourably  of  me. 
On  Feb.  i;th  he  wrote  to  me  an  autograph  letter  offering  a 
pension  of  £300  per  annum,  with  no  terms  of  any  kind,  and 
allowing  it  to  be  settled  if  I  should  think  fit  on  my  wife. 
I  wrote  on  Feb.  i8th  accepting  it  for  my  wife.  In  a  few 
days  the  matter  went  through  the  formal  steps,  and  Mr 
Whewell  and  Mr  Sheepshanks  were  nominated  trustees  for 
my  wife.  The  subject  came  before  Parliament,  by  the  Whig 
Party  vindicating  their  own  propriety  in  having  offered  me 
the  office  of  Astronomer  Royal  in  the  preceding  year ;  and 
Spring  Rice's  letter  then  written  to  me  was  published  in  the 
Times,  &c." 


The  correspondence  relating  to  the  pension  above-men- 
tioned is  given  below,  and  appears  to  be  of  interest,  both  as 
conveying  in  very  felicitous  terms  the  opinion  of  a  very 
eminent  statesman  on  the  general  subject  of  such  pensions, 
and  as  a  most  convincing  proof  of  the  lofty  position  in  Science 
which  the  subject  of  this  Memoir  had  then  attained. 


106  GEORGE   BIDDELL  AIRY. 


WHITEHALL  GARDENS, 
Feb.  17  1835. 

SIR, 

You  probably  are  aware  that  in  a  Resolution  voted  by  the 
House  of  Commons  in  the  last  Session  of  Parliament,  an  opinion 
was  expressed,  that  Pensions  on  the  Civil  List,  ought  not  thereafter 
to  be  granted  by  the  Crown  excepting  for  the  satisfaction  of  certain 
public  claims,  among  which  those  resting  on  Scientific  or  Literary 
Eminence  were  especially  mentioned. 

I  trust  that  no  such  Resolution  would  have  been  necessary  to 
induce  me  as  Minister  of  the  Crown  fully  to  recognize  the  justice  of 
such  claims,  but  I  refer  to  the  Resolution,  as  removing  every  im- 
pediment to  a  Communication  of  the  nature  of  that  which  I  am 
about  to  make  to  you. 

In  acting  upon  the  Principle  of  the  Resolution  in  so  far  as  the 
Claims  of  Science  are  concerned,  my  first  address  is  made  to  you, 
and  made  directly,  and  without  previous  communication  with  any 
other  person,  because  it  is  dictated  exclusively  by  public  considera- 
tions, and  because  there  can  be  no  advantage  in  or  any  motive  for 
indirect  communication. 

I  consider  you  to  have  the  first  claim  on  the  Royal  Favour  which 
Eminence  in  those  high  Pursuits  to  which  your  life  is  devoted,  can 
give,  and  I  fear  that  the  Emoluments  attached  to  your  appointment 
in  the  University  of  Cambridge  are  hardly  sufficient  to  relieve  you 
from  anxiety  as  to  the  Future  on  account  of  those  in  whose  welfare 
you  are  deeply  interested. 

The  state  of  the  Civil  List  would  enable  me  to  advise  the  King 
to  grant  a  pension  of  three  hundred  pounds  per  annum,  and  if  the 
offer  be  acceptable  to  you  the  Pension  shall  be  granted  either  to 
Mrs  Airy  or  yourself  as  you  may  prefer. 

I  beg  you  distinctly  to  understand  that  your  acquiescence  in  this 
Proposal,  will  impose  upon  you  no  obligation  personal  or  political  in 
the  slightest  degree.  I  make  it  solely  upon  public  grounds,  and  I  ask 
you,  by  the  acceptance  of  it,  to  permit  the  King  to  give  some  slight 
encouragement  to  Science,  by  proving  to  those  who  may  be  disposed 
to  follow  your  bright  Example,  that  Devotion  to  the  highest  Branches 
of  Mathematical  and  Astronomical  Knowledge  shall  not  necessarily 


AT   CAMBRIDGE  OBSERVATORY. 


involve  them  in  constant  solicitude  as  to  the  future  condition  of 
those,  for  whom  the  application  of  the  same  Talents  to  more  lucra- 
tive Pursuits  would  have  ensured  an  ample  Provision. 

I  have  the  honor  to  be,  Sir, 

With  true  Respect  and  Esteem, 
Your  faithful  Servant, 

ROBERT   PEEL. 

Mr  Professor  Airy, 

&>£,    6°<T., 

Cambridge. 


OBSERVATORY,  CAMBRIDGE, 
1835,  Feb.  1 8. 

SIR, 

I  have  the  honor  to  acknowledge  your  letter  of  the 
acquainting  me  with  your  intention  of  advising  the  King  to  grant  a 
pension  of  ^300  per  annum  from  the  Civil  List  to  me  or  Mrs  Airy. 

I  trust  you  will  believe  that  I  am  sensible  of  the  flattering  terms 
in  which  this  offer  is  made,  and  deeply  grateful  for  the  considerate 
manner  in  which  the  principal  arrangement  is  left  to  my  choice,  as 
well  as  for  the  freedom  from  engagement  in  which  your  offer  leaves 
me.  I  beg  to  state  that  I  most  willingly  accept  the  offer.  I  should 
prefer  that  the  pension  be  settled  on  Mrs  Airy  (by  which  I  under- 
stand that  in  case  of  her  surviving  me  the  pension  would  be  con- 
tinued to  her  during  her  life,  or  in  the  contrary  event  would  cease 
with  her  life). 

I  wish  that  I  may  have  the  good  fortune  to  prove  to  the  world 
that  I  do  not  accept  this  offer  without  an  implied  engagement  on 
my  part.  I  beg  leave  again  to  thank  you  for  your  attention,  and  to 
assure  you  that  the  form  in  which  it  is  conveyed  makes  it  doubly 
acceptable. 

With  sincere  respect  I  have  the  honor  to  be,  Sir, 
Your  very  faithful  Servant, 

G.    B.    AIRY. 

The  Right  Hon.  Sir  Robert  Peel,  Bart., 
First  Lord  of  the  Treasury,  6°<r.,  &>c. 


108  GEORGE   BIDDELL  AIRY. 

WHITEHALL, 

Feb.  igth  1835. 
SIR, 

I  will  give  immediate  directions  for  the  preparation  of 
the  Warrant  settling  the  Pension  on^Mrs  Airy — the  effect  of  which 
will  be,  as  you  suppose,  to  grant  the'  Pension  to  her  for  her  life.  I 
assure  you  I  never  gave  an  official  order,  which  was  accompanied 
with  more  satisfaction  to  myself  than  this. 

I  have  the  honor  to  be,  Sir. 

Your  faithful  Servant, 

ROBERT   PEEL. 
Mr  Professor  Airy, 

6°<r.,  6°<r., 

Cambridge. 


"On  March  i8th  1835  I  started  (meeting  Sheepshanks  at 
Kingstown)  for  Ireland.  We  visited  Dublin  Observatory, 
and  then  went  direct  to  Markree  near  Sligo,  to  see  Mr 
Cooper's  telescope  (our  principal  object).  We  passed  on  our 
return  by  Enniskillen  and  BallyjamesdurT,  where  my  former 
pupil  P.  Morton  was  living,  and  returned  on  Apr.  3rd. — On 
Apr.  2Oth  I  was  elected  to  the  Royal  Society,  Edinburgh. — 
Apr.  22nd  my  wife  wrote  me  from  Edensor  that  her  sister 
Florence  was  very  ill :  she  died  shortly  after. — On  May  4th  I 
began  lectures  and  finished  on  May  2Qth  :  there  were  58 
names. — My  former  pupil  Guest  asks  my  interest  for  the 
Recordership  of  Birmingham. — In  June  was  circulated  the 
Syndicate  Report  on  the  Observatory. — The  date  of  the 
Preface  to  the  1834  Observations  is  June  i6th. 

"  The  Ministry  had  been  again  changed  in  the  spring,  and 
the  Whigs  were  again  in  power.  On  June  nth  Lord  Auck- 
land, who  was  again  First  Lord  of  the  Admiralty  (as  last 
year),  again  wrote  to  me  to  offer  me  the  office  of  Astronomer 
Royal,  or  to  request  my  suggestions  on  the  filling  up  of  the 
office.  On  June  i5th  I  wrote  my  first  reply,  and  on  June 
I /th  wrote  to  accept  it.  On  June  i8th  Lord  Auckland 
acknowledges,  and  on  June  22nd  the  King  approved.  Lord 


AT   CAMBRIDGE   OBSERVATORY,  log 

Auckland  appointed  to  see  me  on  Friday,  June  23rd,  but  I 
was  unwell.  I  had  various  correspondence  with  Lord  Auck- 
land, principally  about  buildings,  and  had  an  appointment 
with  him  for  August  I3th.  As  Lord  Auckland  was  just 
quitting  office,  to  go  to  India,  I  was  introduced  to  Mr  Charles 
Wood,  the  Secretary  of  the  Admiralty,  with  whom  principally 
the  subsequent  business  was  transacted.  At  this  meeting 
Lord  Auckland  and  Mr  Wood  expressed  their  feeling,  that 
the  Observatory  had  fallen  into  such  a  state  of  disrepute  that 
the  whole  establishment  ought  to  be  cleared  out.  I  repre- 
sented that  I  could  make  it  efficient  with  a  good  First  Assis- 
tant ;  and  the  other  Assistants  were  kept.  But  the  establish- 
ment was  in  a  queer  state.  The  Royal  Warrant  under  the 
Sign  Manual  was  sent  on  August  nth.  It  was  understood 
that  my  occupation  of  office  would  commence  on  October  1st, 
but  repairs  and  alterations  of  buildings  would  make  it  impos- 
sible for  me  to  reside  at  Greenwich  before  the  end  of  the 
year.  On  Oct.  ist  I  went  to  the  Observatory,  and  entered 
formally  upon  the  office  (though  not  residing  for  some  time). 
Oct.  /th  is  the  date  of  my  Official  Instructions. 

"  I  had  made  it  a  condition  of  accepting  the  office  that 
the  then  First  Assistant  should  be  removed,  and  accordingly 
I  had  the  charge  of  seeking  another.  I  determined  to  have  a 
man  who  had  taken  a  respectable  Cambridge  degree.  I 
made  enquiry  first  of  Mr  Bowstead  (brother  to  the  bishop) 
and  Mr  Steventon :  at  length,  consulting  Mr  Hopkins  (a 
well-known  private  tutor  at  Cambridge),  he  recommended  to 
me  Mr  Robert  Main,  of  Queens'  College,  with  whom  I  corre- 
sponded in  the  month  (principally)  of  August,  and  whom  on 
August  30th  I  nominated  to  the  Admiralty.  On  Oct.  2ist 
F.  W.  Simms,  one  of  the  Assistants  (who  apparently  had 
hoped  for  the  office  of  First  Assistant,  for  which  he  was 
quite  incompetent)  resigned  ;  and  on  Dec.  4th  I  appointed 
in  his  place  Mr  James  Glaisher,  who  had  been  at  Cambridge 
from  the  beginning  of  1833,  an<^  on  Dec.  loth  the  Admiralty 
approved. 


HO  GEORGE   BIDDELL   AIRY. 

"  During  this  quarter  of  a  year  I  was  residing  at  Cam- 
bridge Observatory,  visiting  Greenwich  once  a  week  (at  least 
for  some  time),  the  immediate  superintendence  of  the  Obser- 
vatory being  placed  with  Mr  Main.  I  was  however  engaged 
in  reforming  the  system  of  the  Greenwich  Observatory,  and 
prepared  and  printed  30  skeleton  forms  for  reductions  of 
observations  and  other  business.  On  Dec.  I4th  I  resigned 
my  Professorship  to  the  Vice-Chancellor.  But  I  continued 
the  reduction  of  the  observations,  so  that  not  a  single  figure 
was  left  to  my  successor :  the  last  observations  were  those  of 
Halley's  Comet.  The  Preface  to  my  1835  Cambridge  Obser- 
vations is  dated  Aug.  22nd,  1836. 

"In  regard  to  the  Northumberland  Telescope,  I  had 
for  some  time  been  speculating  on  plans  of  mounting  and 
enclosing  the  instrument,  and  had  corresponded  with  Simms, 
A.  Biddell,  Cubitt,  and  others  on  the  subject.  On  Apr.  24th 
Tulley  the  younger  was  endeavouring  to  adjust  the  object- 
glass.  On  May  3ist  I  plainly  asked  the  Duke  of  Northum- 
berland whether  he  would  defray  the  expense  of  the  mount- 
ing and  building.  On  June  4th  he  assented,  and  money  was 
placed  at  a  banker's  to  my  order.  I  then  proceeded  in 
earnest:  in  the  autumn  the  building  was  erected,  and  the 
dome  was  covered  before  the  depth  of  winter.  I  continued 
in  1836  to  superintend  the  mounting  of  the  instrument. 

"In  regard  to  the  Planetary  Reductions:  to  July  nth 
J.  Glaisher  had  been  employed  27  weeks,  and  from  July  I  ith  to 
Jan.  i6th,  1836,  25  weeks.  Mr  Spring  Rice,  when  Chancellor 
of  the  Exchequer,  had  promised  money,  but  no  official  minute 
had  been  made,  and  no  money  had  been  granted.  On  Aug. 
2  ist  I  applied  to  Mr  Baring  (Secretary  of  the  Treasury). 
After  another  letter  he  answered  on  Oct.  I5th  that  he  found 
no  official  minute.  After  writing  to  Vernon  Harcourt  and  to 
Spring  Rice,  the  matter  was  arranged :  my  outlay  was  re- 
funded, and  another  sum  granted. — In  regard  to  Groom- 
bridge's  Observations,  I  find  that  on  Dec.  i6th  certain 
trial  reductions  had  been  made  under  my  direction  by 


AT   CAMBRIDGE   OBSERVATORY.  Ill 

J.  Glaisher. — I  had  attempted  some  optical  experiments  in 
the  summer,  especially  on  the  polarization  of  sky-light ;  but 
had  been  too  busy  with  the  Observatory  to  continue  them. 

"  In  August  my  wife  was  in  a  critical  state  of  health. — In 
December  I  received  information  regarding  merchant  ships' 
chronometers,  for  which  I  had  applied  to  Mr  Charles  Parker 
of  Liverpool. — On  Dec.  8th  Mr  Spring  Rice  and  Lord  John 
Russell  offered  me  knighthood,  but  I  declined  it. — On  July 
23rd  I  went  into  Suffolk  with  my  wife's  sisters  Elizabeth  and 
Georgiana,  and  returned  on  August  3rd :  this  was  all  the 
holiday  that  I  got  in  this  year. — On  the  I4th  of  August  I 
saw  Mr  Taylor,  the  Admiralty  Civil  Architect  in  London, 
and  the  extension  of  buildings  at  Greenwich  Observatory 
was  arranged. — I  made  various  journeys  to  Greenwich,  and 
on  Dec.  i;th,  having  sent  off  our  furniture,  we  all  quitted  the 
Cambridge  Observatory,  and  stayed  for  some  days  at  the 
house  of  Miss  Sheepshanks. 

"  Thus  ended  a  busy  and  anxious  year." 


With  reference  to  the  offer  of  knighthood  above-men- 
tioned, Airy's  reply  is  characteristic,  and  the  short  corre- 
spondence relating  to  it  is  therefore  inserted. — The  offer 
itself  is  an  additional  proof  of  the  high  estimation  in  which 
he  stood  at  this  time. 

DOWNING  STREET, 

Dec.  8tti  1835. 
MY  DEAR  SIR, 

I  have  been  in  communication  with  my  colleague  Lord 
John  Russell  which  has  made  me  feel  rather  anxious  to  have  the 
pleasure  of  seeing  you,  but  on  second  thoughts  it  has  occurred  to  me 
that  the  subject  of  my  communication  would  render  it  more  satisfac- 
tory to  you  to  receive  a  letter  than  to  pay  a  visit. 

In  testimony  of  the  respect  which  is  felt  for  your  character  and 
acquirements,  there  would  be  every  disposition  to  recommend  you  to 
His  Majesty  to  receive  the  distinction  of  Knighthood.  I  am  quite 
aware  that  to  you  individually  this  may  be  a  matter  of  small  concern, 


112  GEORGE   BIDDELL  AIRY. 

but  to  the  scientific  world  in  general  it  will  not  be  indifferent,  and  to 
foreign  countries  it  will  mark  the  consideration  felt  for  you  personally 
as  well  as  for  the  position  which  you  occupy  among  your  learned 
contemporaries. 

From  a  knowledge  of  the  respecfand  esteem  which  I  feel  for  you 
Lord  John  Russell  has  wished  that  the  communication  should  be 
made  through  me  rather  than  through  any  person  who  had  not  the 
pleasure  of  your  acquaintance.  K 

Pray  let  me  hear  from  you  and  believe  me  my  dear  Sir,  with 
compliments  to  Mrs  Airy, 

Very  truly  yours, 

T.    SPRING   RICE. 

P.S. — It  may  be  right  to  add  that  when  a  title  of  honor  is  con- 
ferred on  grounds  like  those  which  apply  to  your  case,  no  fees  or 
charges  of  any  kind  would  be  payable. 

OBSERVATORY,  CAMBRIDGE, 
1835,  Dec.  loth. 

MY  DEAR  SIR, 

I  beg  to  acknowledge  your  letter  of  the  8th,  which  I  have 
received  at  this  place,  conveying  to  me  an  intimation  of  the  wish  of 
His  Majesty's  Ministers  to  recommend  me  to  the  King  for  the  honor 
of  Knighthood. 

I  beg  to  assure  you  that  I  am  most  sensible  to  the  liberality 
which  I  have  experienced  from  the  Government  in  other  as  well  as 
in  pecuniary  matters,  and  that  I  am  very  highly  gratified  by  the  con- 
sideration (undeserved  by  me,  I  fear)  which  they  have  displayed  in 
the  present  instance.  And  if  I  now  request  permission  to  decline 
the  honor  offered  to  me,  I  trust  I  may  make  it  fully  understood  that 
it  is  not  because  I  value  it  lightly  or  because  I  am  not  anxious  to 
receive  honors  from  such  a  source. 

The  unalterable  custom  of  this  country  has  attached  a  certain 
degree  of  light  consideration  to  titles  of  honor  which  are  not  sup- 
ported by  considerable  fortune  ;  or  at  least,  it  calls  for  the  display  of 
such  an  establishment  as  may  not  be  conveniently  supported  by 
even  a  comfortable  income.  The  provision  attached  to  my  official 
situation,  and  the  liberality  of  the  King  towards  one  of  the  members 
of  my  family,  have  placed  me  in  a  position  of  great  comfort.  These 
circumstances  however  have  bound  me  to  consider  myself  as  the 
devoted  servant  of  the  country,  and  to  debar  myself  from  efforts  to 


AT   CAMBRIDGE  OBSERVATORY.  113 

increase  my  fortune  which  might  otherwise  have  been  open  to  me. 
I  do  not  look  forward  therefore  to  any  material  increase  of  income, 
and  that  which  I  enjoy  at  present  is  hardly  sufficient,  in  my  opinion, 
to  support  respectably  the  honor  which  you  and  Lord  John  Russell 
have  proposed  to  confer  upon  me.  For  this  reason  only  I  beg  leave 
most  respectfully  to  decline  the  honor  of  Knighthood  at  the  present 
time. 

I  have  only  to  add  that  my  services  will  always  be  at  the  com- 
mand of  the  Government  in  any  scientific  subject  in  which  I  can  be 
of  the  smallest  use. 

I  am,  my  dear  Sir, 

Your  very  faithful  Servant, 

G.    B.   AIRY. 
The  Right  Honorable  T.  Spring  Rice. 


"In  brief  revision  of  the  years  from  1827  to  1835  I  may 
confine  myself  to  the  two  principal  subjects — my  Professorial 
Lectures,  and  my  Conduct  of  the  Cambridge  Observatory. 

"The  Lectures  as  begun  in  1827  included  ordinary 
Mechanics,  ordinary  Hydrostatics  and  Pneumatics  (I  think 
that  I  did  not  touch,  or  touched  very  lightly,  on  the  subjects 
connected  with  the  Hydraulic  Ram),  and  ordinary  Optics 
(with  a  very  few  words  on  Polarization  and  Depolarization). 
In  1828  the  two  first  were  generally  improved,  and  for  the 
third  (Optics)  I  introduced  a  few  words  on  Circular  Polariza- 
tion. I  believe  that  it  was  in  1829  that  I  made  an  addition 
to  the  Syllabus  with  a  small  engraving,  shewing  the  inter- 
ference of  light  in  the  best  practical  experiment  (that  of  the 
flat  prism) ;  and  I  went  thoroughly  into  the  main  points  of 
the  Undulatory  Theory,  interference,  diffraction,  &c.  In  1830 
I  believe  I  went  (in  addition  to  what  is  mentioned  above)  into 
Polarization  and  Depolarization  of  all  kinds.  My  best  lec- 
ture diagrams  were  drawn  and  painted  by  my  wife.  The 
Lectures  were  universally  pronounced  to  be  valuable.  The 
subjects  underwent  no  material  change  in  1831,  2,  3,  4,  5; 
and  I  believe  it  was  a  matter  of  sincere  regret  to  many 

A.  B.  8 


114  GEORGE   BIDDELL  AIRY. 

persons  that  my  removal  to  Greenwich  terminated  the  series. 
Each  lecture  nominally  occupied  an  hour.  But  I  always 
encouraged  students  to  stop  and  talk  with  me;  and  this 
supplement  was  usually  considered  a  valuable  part  of  the 
lecture.  Practically  the  lecture7,  on  most  days,  occupied  two 
hours.  I  enjoyed  the  Lectures  much  :  yet  I  felt  that  the 
labour  (in  addition  to  other  work)  made  an  impression  on  my 
strength,  and  I  became  at  length  desirous  of  terminating 
them. 

"  The  Observatory,  when  I  took  charge  of  it,  had  only  one 
instrument — the  Transit-Instrument.  The  principles  how- 
ever which  I  laid  down  for  my  own  direction  were  adapted 
to  the  expected  complete  equipment.  Planets  (totally  neg- 
lected at  Greenwich)  were  to  be  observed.  Observations 
were  to  be  reduced  completely,  and  the  reductions  were  to  be 
exhibited  in  an  orderly  way :  this  was  a  novelty  in  Astro- 
nomy. I  considered  it  so  important  that  I  actually  proposed 
to  omit  in  my  publication  the  original  observations,  but  was 
dissuaded  by  Herschel  and  others.  I  sometimes  suspended 
observations  for  a  short  time,  in  order  to  obtain  leisure  for 
the  reductions.  I  had  at  first  no  intention  of  correcting  the 
places  of  the  fundamental  stars  as  settled  at  Greenwich.  But 
I  found  myself  compelled  to  do  so,  because  they  were  not 
sufficiently  accurate ;  and  then  I  took  the  course  of  observing 
and  reducing  as  an  independent  observer,  without  reference 
to  any  other  observatory.  I  introduced  the  principle  of  not 
correcting  instrumental  errors,  but  measuring  them  and  apply- 
ing numerical  corrections.  I  determined  my  longitude  by 
chronometers,  and  my  latitude  by  a  repeating  circle  borrowed 
from  Mr  Sheepshanks,  which  I  used  so  well  that  the  result 
was  only  half  a  second  in  error.  The  form  of  my  reductions 
in  the  published  volume  for  1828  is  rather  irregular,  but  the 
matter  is  good  :  it  soon  attracted  attention.  In  1829  the 
process  was  much  the  same :  I  had  an  assistant,  Mr  Baldrey. 
In  1830  still  the  same,  with  the  additions: — that  I  formally 
gave  the  corrections  of  relative  right-ascension  of  fundamental 


AT   CAMBRIDGE   OBSERVATORY.  1 15 

stars  (without  alteration  of  equinox,  which  I  had  not  the 
means  of  obtaining)  to  be  used  in  the  year  1831 ;  and  that  I 
reduced  completely  the  observed  occultations  (with  a  small 
error,  subsequently  corrected).  In  1831  the  system  of  correc- 
tion of  broken  transits  was  improved  :  the  errors  of  assumed 
R.  A.  of  Fundamental  Stars  were  exhibited :  Mean  Solar 
Time  was  obtained  from  Sidereal  Time  by  time  of  Transit 
of  T  (computed  by  myself) :  the  method  of  computing  occul- 
tations was  improved.  In  1832  the  small  Equatoreal  was 
erected,  and  was  soon  employed  in  observations  of  the  elon- 
gation of  the  4th  Satellite  of  Jupiter  for  determining  the 
mass  of  Jupiter.  The  Mural  Circle  was  erected  at  the  end  of 
the  year,  but  not  used.  The  calculation  of  R.  A.  of  Funda- 
mental Stars  was  made  homogeneously  with  the  others : 
separate  results  of  all  were  included  in  ledgers :  a  star-cata- 
logue was  formed:  all  as  to  the  present  time  (1871).  With 
the  Equatoreal  the  difference  of  N.  P.  D.  of  Mars  and  stars 
was  observed. 

"With  the  beginning  of  1833  the  Mural  Circle  was  estab- 
lished at  work,  a  second  assistant  (Mr  Glaisher)  was  appointed, 
and  the  Observatory  might  be  considered  complete.  I  made 
experiments  on  the  graduations  of  the  Circle.  I  detected 
and  was  annoyed  by  the  R— D.  I  determined  the  latitude. 
I  exhibited  the  separate  results  for  N.  P.  D.  of  stars  in  ledger, 
and  their  means  in  Catalogue.  I  investigated  from  my  obser- 
vations the  place  of  equinox  and  the  obliquity  of  the  ecliptic. 
I  made  another  series  of  observations  of  Jupiter's  4th  Satel- 
lite, for  the  mass  of  Jupiter.  I  observed  the  solar  eclipse 
with  the  Equatoreal,  by  a  method  then  first  introduced, 
which  I  have  since  used  several  times  at  Cambridge  and 
Greenwich  with  excellent  effect.  The  Moon  and  the  Planets 
were  usually  observed  till  near  two  in  the  morning.  Correc- 
tion for  defective  illumination  applied  when  necessary.  The 
volume  is  very  complete,  the  only  deficiency  being  in  the 
observation  of  Moon  and  Planets  through  the  severe  morning 
hours.  In  1834  the  only  novelties  are — examination  of  the 

8—2 


Il6  GEORGE  BIDDELL  AIRY. 

graduations  of  the  declination  circle  of  the  Equatoreal  (exces- 
sively bad):  observations  of  a  spot  on  Jupiter  for  rotation, 
and  of  Mars  and  stars.  In  1835  (including  January  1836) 
there  is  a  more  complete  examination  of  the  Equatoreal 
graduations  :  parallax  and  refraction  for  Equatoreal  observa- 
tions :  a  spot  on  Jupiter :  a  series  of  observations  on  Jupiter's 
4th  Satellite  for  the  mass  of  Jupiter:  Mars, and  stars:  Hal- 
ley's  Comet  (the  best  series  of  observations  which  could  be 
made  in  the  season) :  and  a  short  series  of  meteorological 
observations,  on  a  plan  suggested  by  Sir  John  Herschel  then 
at  the  Cape  of  Good  Hope. 

"  I  cannot  tell  precisely  in  which  year  I  introduced  the 
following  useful  custom.  Towards  the  end  of  each  year  I 
procured  a  pocket-book  for  the  following  year  with  a  space 
for  every  day,  and  carefully  examining  all  the  sources  of 
elements  of  observations,  and  determining  the  observations 
to  be  made  every  day,  I  inserted  them  in  the  pocket-book. 
This  system  gave  wonderful  steadiness  to  the  plan  of  obser- 
vations for  the  next  year.  The  system  has  been  maintained 
in  great  perfection  at  the  Observatory  of  Greenwich.  (The 
first  of  these  pocket-books  which  Prof.  Adams  has  found  is 
that  for  1833.)  Printed  skeleton  forms  were  introduced  for 
all  calculations  from  1828.  In  the  Greenwich  Observatory 
Library  there  is  a  collection,  I  believe  complete,  of  printed 
papers  commencing  with  my  manifesto,  and  containing  all 
Syndicate  Reports  except  for  1833  (when  perhaps  there  was 
none).  It  seems  from  these  that  my  first  written  Report  on 
Observations,  &c.,  was  on  May  3Oth,  1834.  The  first  Syndi- 
cate Report  is  on  May  25th,  1829." 


A  few  remarks  on  Airy's  private  life  and  friends  during 
his  residence  at  Cambridge  Observatory  may  be  here  appro- 
priately inserted. 

Amid  the  laborious  occupations  recorded  in  the  foregoing 
pages,  his  social  life  and  surroundings  appear  to  have  been 


AT  CAMBRIDGE  OBSERVATORY.  1 I? 

most  pleasant  and  congenial.  At  that  period  there  were  in 
residence  in  Cambridge,  and  particularly  at  Trinity,  a  large 
number  of  very  brilliant  men.  Airy  was  essentially  a  Cam- 
bridge man.  He  had  come  up  poor  and  friendless  :  he  had 
gained  friends  and  fame  at  the  University,  and  his  whole 
work  had  been  done  there.  From  the  frequent  references  in 
after  times  both  by  him  and  his  wife  to  their  life  at  Cam- 
bridge, it  is  clear  that  they  had  a  very  pleasant  recollection 
of  it,  and  that  the  social  gatherings  there  were  remarkably 
attractive.  He  has  himself  recorded  that  with  Whewell  and 
Sedgwick,  and  his  accomplished  sisters-in-law,  who  were 
frequently  on  long  visits  at  the  Observatory,  they  formed 
pretty  nearly  one  family. 

His  friendship  with  Whewell  was  very  close.  Although 
Whewell  was  at  times  hasty,  and  rough-mannered,  and  even 
extremely  rude,  yet  he  was  generous  and  large-minded,  and 
thoroughly  upright1.  In  power  of  mind,  in  pursuits,  and 
interests,  Airy  had  more  in  common  with  Whewell  than  with 
any  other  of  his  friends.  It  was  with  Whewell  that  he  under- 
took the  experiments  at  Dolcoath :  it  was  to  Whewell  that 
he  first  communicated  the  result  of  his  remarkable  investiga- 
tion of  the  Long  Inequality  of  Venus  and  the  Earth;  and 
some  of  his  Optical  researches  were  conducted  jointly  with 
Whewell.  Whewell  took  his  degree  in  1816,  seven  years 
before  Airy,  and  his  reputation,  both  for  mathematical  and 
all-round  knowledge,  was  extremely  and  deservedly  great, 
but  he  was  always  most  generous  in  his  recognition  of  Airy's 
powers.  Thus  in  a  letter  of  Mar.  i6th,  1823  (Life  of  William 
Whewell  by  Mrs  Stair  Douglas),  he  says,  "Airy  is  certainly  a 
most  extraordinary  man,  and  deserves  everything  that  can 

1  The  following  passage  occurs  in  a  letter  from  Airy  to  his  wife,  dated  1845, 
Sept.  lyth: 

"  I  am  sorry  that  *  *  *  *  speaks  in  such  terms  of  the  '  Grand  Master,'  as  she 
used  to  be  so  proud  of  him  :  it  is  only  those  who  have  well  gone  through  the 
ordeal  of  quarrels  with  him  and  almost  insults  from  him,  like  Sheepshanks  and 
me,  that  thoroughly  appreciate  the  good  that  is  in  him  :  I  am  sure  he  will  never 
want  a  good  word  from  me." 


Il8  GEORGE  BIDDELL  AIRY. 

be  said  of  him"  ;  and  again  in  the  autumn  of  1826  he  writes 
to  his  aunt,  "You  mentioned  a  difficulty  which  had  occurred 
to  you  in  one  of  your  late  letters ;  how  Airy  should  be  made 
Professor  while  I  was  here,  who,"  being  your  nephew,  must  of 
course,  on  that  account,  deserve  it  better  than  he  could. 
Now  it  is  a  thing  which  you  will  think  odd,  but  it  is  never- 
theless true,  that  Airy  is  a  better  mathematician  than  your 
nephew,  and  has  moreover  been  much  more  employed  of  late 

in  such  studies Seriously  speaking,  Airy  is   by  very 

much  the  best  person  they  could  have  chosen  for  the  situa- 
tion, and  few  things  have  given  me  so  much  pleasure  as  his 
election."  How  much  Whewell  depended  upon  his  friends 
at  the  Observatory  may  be  gathered  from  a  letter  which  he 
wrote  to  his  sister  on  Dec.  2ist,  1833.  "  We  have  lately  been 
in  alarm  here  on  the  subject  of  illness.  Two  very  near  friends 
of  mine,  Prof,  and  Mrs  Airy,  have  had  the  scarlet  fever  at 
the  same  time ;  she  more  slightly,  he  very  severely.  They 
are  now,  I  am  thankful  to  say,  doing  well  and  recovering 
rapidly.  You  will  recollect  that  I  was  staying  with  them  at 
her  father's  in  Derbyshire  in  the  summer.  They  are,  I  think, 
two  of  the  most  admirable  and  delightful  persons  that  the 
world  contains."  And  again  on  Dec.  2Oth,  1835,  he  wrote  to 
his  sister  Ann,  "  My  friends — I  may  almost  say  my  dearest 
friends — Professor  Airy  and  his  family  have  left  Cambridge, 
he  being  appointed  Astronomer  Royal  at  Greenwich — to  me 
an  irreparable  loss ;  but  I  shall  probably  go  and  see  how 
they  look  in  their  new  abode."  Their  close  intercourse  was 
naturally  interrupted  by  Airy's  removal  to  Greenwich,  but 
their  friendly  feelings  and  mutual  respect  continued  without 
material  break  till  Whewell's  death.  There  was  frequent 
correspondence  between  them,  especially  on  matters  con- 
nected with  the  conduct  and  teaching  of  the  University,  in 
which  they  both  took  a  keen  interest,  and  a  warm  welcome 
at  Trinity  Lodge  always  awaited  Mr  and  Mrs  Airy  when 
they  visited  Cambridge.  In  a  letter  written  to  Mrs  Stair 
Douglas  on  Feb.  nth,  1882,  enclosing  some  of  Whewell's 


AT  CAMBRIDGE  OBSERVATORY.  119 

letters,  there  occurs  the  following  passage :  "  After  the  decease 
of  Mrs  Whewell,  Whewell  wrote  to  my  wife  a  mournful  letter, 
telling  her  of  his  melancholy  state,  and  asking  her  to  visit 
him  at  the  Lodge  for  a  few  days.  And  she  did  go,  and  did 
the  honours  of  the  house  for  several  days.  You  will  gather 
from  this  the  relation  in  which  the  families  stood."  Whewell 
died  on  Mar.  6th,  1866,  from  the  effects  of  a  fall  from  his 
horse,  and  the  following  extract  is  from  a  letter  written  by 
Airy  to  Whewell's  niece,  Mrs  Sumner  Gibson,  on  hearing  of 
the  death  of  his  old  friend  : 

"  The  Master  was,  I  believe,  my  oldest  surviving  friend 
(beyond  my  own  family),  and,  after  an  acquaintance  of  46 
years,  I  must  have  been  one  of  his  oldest  friends.  We  have 
during  that  time  been  connected  privately  and  officially :  we 
travelled  together  and  experimented  together :  and  as  oppor- 
tunity served  (but  I  need  not  say  in  very  different  degrees) 
we  both  laboured  for  our  College  and  University.  A  terrible 
blank  is  left  on  my  mind." 

Sedgwick  was  probably  1 5  years  older  than  Airy :  he 
took  his  degree  in  1808.  But  the  astonishing  buoyancy  of 
spirits  and  bonhomie  of  Sedgwick  fitted  him  for  all  ages 
alike.  He  was  undoubtedly  the  most  popular  man  in  Cam- 
bridge in  modern  times.  His  ability,  his  brightness  and  wit, 
his  fearless  honesty  and  uprightness,  his  plain-speaking  and 
good  humour,  rendered  him  a  universal  favourite.  His  close 
alliance  with  Airy  was  much  more  social  than  scientific.  It 
is  true  that  they  made  some  geological  excursions  together, 
but,  at  any  rate  with  Airy,  it  was  far  more  by  way  of  recrea- 
tion than  of  serious  study,  and  Sedgwick's  science  was  entirely 
geological.  Their  friendship  continued  till  Sedgwick's  death, 
though  it  was  once  or  twice  imperilled  by  Sedgwick's  impul- 
sive and  hasty  nature. 

Peacock  took  his  degree  in  1813  (Herschel's  year),  and 
was  therefore  probably  10  years  older  than  Airy.  He  was 
the  earliest  and  staunchest  friend  of  Airy  in  his  undergraduate 
years,  encouraged  him  in  every  possible  way,  lent  him  books, 


I2O  GEORGE   BIDDELL  AIRY. 

assisted  him  in  his  studies,  helped  him  with  wise  advice  on 
many  occasions,  and  took  the  greatest  interest  in  his  success. 
He  was  a  good  and  advanced  mathematician,  and  with  a 
great  deal  of  shrewdness  and  Common-sense  he  united  a 
singular  kindness  and  gentleness  of  manner.  It  is  therefore 
not  to  be  wondered  at  that  he  was  regarded  by  Airy  with  the 
greatest  esteem  and  affection,  and  though  they  were  after- 
wards separated,  by  Peacock  becoming  Dean  of  Ely  and 
Airy  Astronomer  Royal,  yet  their  warm  friendship  was  never 
broken.  The  following  letter,  written  by  Airy  to  Mrs  Pea- 
cock on  receiving  the  news  of  the  death  of  the  Dean,  well 
expresses  his  feelings  towards  his  old  friend  : 


TRINITY  LODGE,  CAMBRIDGE, 
1858,  Dec.  4. 

MY  DEAR  MADAM, 

I  have  desired  for  some  time  to  express  to  you  my 
sympathies  on  occasion  of  the  sad  bereavement  which  has  come 
upon  me  perhaps  as  strongly  as  upon  any  one  not  connected  by 
family  ties  with  my  late  friend.  But  I  can  scarcely  give  you  an  idea 
how  every  disposable  moment  of  my  time  has  been  occupied.  I  am 
now  called  to  Cambridge  on  business,  and  I  seize  the  first  free  time 
to  write  to  you. 

My  late  friend  was  the  first  person  whom  I  knew  in  College  (I 
had  an  introduction  to  him  when  I  went  up  as  freshman).  From 
the  first,  he  desired  me  to  consider  the  introduction  not  as  entitling 
me  to  a  mere  formal  recognition  from  him,  but  as  authorizing  me  at 
all  times  to  call  on  him  for  any  assistance  which  I  might  require. 
And  this  was  fully  carried  out :  I  referred  to  him  in  every  difficulty : 
I  had  the  entire  command  of  his  rooms  and  library  (a  very  important 
aid  in  following  the  new  course  of  mathematics  which  he  had  been 
so  instrumental  in  introducing  into  the  University)  in  his  occasional 
absences :  and  in  all  respects  I  looked  to  him  as  to  a  parent.  All  my 
debts  to  other  friends  in  the  University  added  together  are  not  com- 
parable to  what  I  owe  to  the  late  Dean. 

Latterly  I  need  not  say  that  I  owed  much  to  him  and  that  I  owe 
much  to  you  for  your  kind  notice  of  my  two  sons,  even  since  the  sad 
event  which  has  put  it  out  of  his  power  to  do  more. 


AT  CAMBRIDGE  OBSERVATORY.  121 

In  the  past  summer,  looking  to  my  custom  of  making  a  visit  to 
Cambridge  in  some  part  of  the  October  Term,  I  had  determined  that 
a  visit  to  Ely  this  year  should  not  depend  on  the  chance  of  being 
free  to  leave  Cambridge,  but  that,  if  it  should  be  found  convenient 
to  yourself  and  the  Dean,  the  first  journey  should  be  made  to  Ely. 
I  wish  that  I  had  formed  the  same  resolution  one  or  two  years  ago. 

With  many  thanks  for  your  kindness,  and  with  deep  sympathy  on 
this  occasion, 

I  am, 
My  dear  Madam, 

Yours  very  faithfully, 

G.    B.    AIRY. 


Sheepshanks  was  a  Fellow  of  Trinity,  in  orders :  he  was 
probably  seven  years  older  than  Airy  (he  took  his  degree  in 
1816).  He  was  not  one  of  Airy's  earliest  friends,  but  he  had 
a  great  taste  and  liking  for  astronomy,  and  the  friendship 
between  them  when  once  established  became  very  close.  He 
was  a  very  staunch  and  fearless  friend,  an  able  and  incisive 
writer,  and  remarkably  energetic  and  diligent  in  astronomical 
investigations.  He,  or  his  sister,  Miss  Sheepshanks,  had  a 
house  in  London,  and  Sheepshanks  was  very  much  in  London, 
and  busied  himself  extremely  with  the  work  of  the  Royal 
Observatory,  that  of  the  Board  of  Longitude,  and  miscella- 
neous astronomical  matters.  He  was  most  hospitable  to  his 
friends,  and  while  Airy  resided  at  Cambridge  his  house  was 
always  open  to  receive  him  on  his  frequent  visits  to  town. 
In  the  various  polemical  discussions  on  scientific  matters  in 
which  Airy  was  engaged,  Sheepshanks  was  an  invaluable 
ally,  and  after  Airy's  removal  to  Greenwich  had  more  or  less 
separated  him  from  his  Cambridge  friends,  Sheepshanks  was 
still  associated  with  him  and  took  a  keen  interest  in  his 
Greenwich  work.  And  this  continued  till  Sheepshanks's 
death.  The  warmest  friendship  always  subsisted  between 
the  family  at  the  Observatory  and  Mr  and  Miss  Sheep- 
shanks. 


122  GEORGE   BIDDELL   AIRY. 

There  were  many  other  friends,  able  and  talented  men, 
but  these  four  were  the  chief,  and  it  is  curious  to  note  that 
they  were  all  much  older  than  Airy.  It  would  seem  as  if 
Airy's  knowledge  had  matured  in*  so  remarkable  a  manner, 
and  the  original  work  that  he  produced  was  so  brilliant  and 
copious,  that  by  common  consent  he  ranked  with  men  who 
were  much  his  seniors :  and  the  natural  gravity  and  decorum 
of  his  manners  when  quite  a  young  man  well  supported  the 
idea  of  an  age  considerably  greater  than  was  actually  the 
case. 


CHAPTER    V. 

AT  GREENWICH  OBSERVATORY— 1836  TO  1846. 

1S36 

"  THROUGH  the  last  quarter  of  1835  I  had  kept  everything 
going  on  at  the  Greenwich  Observatory  in  the  same  manner 
in  which  Mr  Pond  had  carried  it  on.  With  the  beginning  of 
1836  my  new  system  began.  I  had  already  prepared  30 
printed  skeleton  forms  (a  system  totally  unknown  to  Mr 
Pond)  which  were  now  brought  into  use.  And,  having  seen 
the  utility  of  the  Copying  Press  in  merchants'  offices,  I 
procured  one.  From  this  time  my  correspondence,  public 
and  private,  is  exceedingly  perfect. 

"At  this  time  the  dwelling  house  was  still  unconnected 
with  the  Observatory.  It  had  no  staircase  to  the  Octagon 
Room.  Four  new  rooms  had  been  built  for  me  on  the 
western  side  of  the  dwelling  house,  but  they  were  not  yet 
habitable.  The  North-east  Dome  ground  floor  was  still  a 
passage  room.  The  North  Terrace  was  the  official  passage 
to  the  North-west  Dome,  where  there  was  a  miserable 
Equatoreal,  and  to  the  25 -foot  Zenith  Tube  (in  a  square 
tower  like  a  steeple,  which  connected  the  N.W.  Dome  with 
Flamsteed's  house).  The  southern  boundary  of  the  garden 
ran  down  a  hollow  which  divides  the  peninsula  from  the  site 
of  the  present  Magnetic  Observatory,  in  such  a  manner  that 
the  principal  part  of  the  garden  was  fully  exposed  to  the 
public.  The  Computing  Room  was  a  most  pitiful  little  room. 
There  was  so  little  room  for  me  that  I  transported  the 
principal  table  to  a  room  in  my  house,  where  I  conducted 


124  GEORGE   BIDDELL  AIRY. 

much  of  my  own  official  business.  A  large  useless  reflecting 
telescope  (Ramage's),  on  the  plan  and  nearly  of  the  size  of 
Sir  W.  Herschel's  principal  telescope,  encumbered  the  centre 
of  the  Front  Court. 

"  On  Jan.  I  ith  I  addressed  Mr  Buck,  agent  of  the  Princess 
Sophia  of  Gloucester,  Ranger  of  Greenwich  Park,  for  leave  to 
enclose  a  portion  of  the  ground  overlooking  "my  garden. 
This  was  soon  granted,  and  I  was  partially  delivered  from 
the  inconvenience  of  the  public  gaze.  The  liberation  was  not 
complete  till  the  Magnetic  ground  was  enclosed  in  1837. 

"  In  the  inferior  departments  of  the  Admiralty,  especially 
in  the  Hydrographic  Office  (then  represented  by  Captain 
Beaufort)  with  which  I  was  principally  connected,  the  Ob- 
servatory was  considered  rather  as  a  place  for  managing 
Government  chronometers  than  as  a  place  of  science.  The 
preceding  First  Assistant  (Taylor)  had  kept  a  book  of  letter 
references,  and  I  found  that  out  of  840  letters,  820  related  to 
Government  chronometers  only.  On  Jan.  I7th  I  mentally 
sketched  my  regulations  for  my  own  share  in  chronometer 
business.  I  had  some  correspondence  with  Captain  Beaufort, 
but  we  could  not  agree,  and  the  matter  was  referred  to  the 
Admiralty.  Finally  arrangements  were  made  which  put  the 
chronometer  business  in  proper  subordination  to  the  scientific 
charge  of  the  Observatory. 

"  In  my  first  negociations  with  the  Admiralty  referring  to 
acceptance  of  the  office  of  Astronomer  Royal,  in  1834,  Lord 
Auckland  being  then  First  Lord  of  the  Admiralty,  I  had  stipu- 
lated that,  as  my  successor  at  Cambridge  would  be  unprepared 
to  carry  on  my  Lectures,  I  should  have  permission  to  give  a 
final  course  of  Lectures  there.  At  the  end  of  1835  Lord 
Auckland  was  succeeded  by  Lord  Minto :  I  claimed  the 
permission  from  him  and  he  refused  it.  When  this  was 
known  in  Cambridge  a  petition  was  presented  by  many 
Cambridge  residents,  and  Lord  Minto  yielded.  On  April 
1 8th  I  went  to  Cambridge  with  my  wife,  residing  at  the  Bull 
Inn,  and  began  Lectures  on  April  2ist:  they  continued 


AT   GREENWICH   OBSERVATORY.  125 

(apparently)  to  May  27th.  My  lecture-room  was  crowded 
(the  number  of  names  was  no)  and  the  lectures  gave  great 
satisfaction.  I  offered  to  the  Admiralty  to  put  all  the  profits 
in  their  hands,  and  transmitted  a  cheque  to  the  Accountant 
General  of  the  Navy  :  but  the  Admiralty  declined  to  receive 
them. 

"  On  June  4th  the  Annual  Visitation  of  the  Observatory 
was  held,  Mr  F.  Baily  in  the  Chair.  I  presented  a  written 
Report  on  the  Observatory  (a  custom  which  I  had  introduced 
at  Cambridge)  in  which  I  did  not  suppress  the  expression  of 
my  feelings  about  chronometer  business.  The  Hydrographer, 
Captain  Beaufort,  who  was  one  of  the  Official  Visitors,  was 
irritated  :  and  by  his  influence  the  Report  was  not  printed. 
I  kept  it  and  succeeding  Reports  safe  for  three  years,  and 
then  the  Board  of  Visitors  agreed  to  print  them ;  and  four 
Reports  were  printed  together,  and  bound  with  the  Greenwich 
Observations  of  1838. 

"  In  the  course  of  this  year  I  completed  the  volume  of 
Observations  made  at  Cambridge  Observatory  in  1835  and 
on  Nov.  loth  the  printed  copies  were  distributed.  About  the 
end  of  1835  the  Dome  for  the  Northumberland  Telescope  was 
erected :  but  apparently  the  polar  frame  was  not  erected." 

The  following  account  of  an  accident  which  occurred 
during  the  construction  of  the  dome  is  extracted  from  a 
letter  by  Airy  to  his  wife  dated  1836  Jan.  3ist.  "The 
workmen's  account  of  the  dome  blowing  off  is  very  curi- 
ous :  it  must  have  been  a  strange  gust.  It  started  suddenly 
when  the  men  were  all  inside  and  Beaumont  was  looking 
up  at  it :  the  cannon  balls  were  thrown  in  with  great  violence 
(one  of  them  going  between  the  spokes  of  Ransomes'  large 
casting),  and  instantly  after  the  dome  had  started,  the  boards 
of  the  outside  scaffolding  which  had  been  tossed  up  by  the 
same  gust  dropped  down  into  the  gap  which  the  dome  had 
left.  It  is  a  wonder  that  none  of  the  men  were  hurt  and  that 
the  iron  was  not  broken.  The  dome  is  quite  covered  and  I 
think  does  not  look  so  well  as  when  the  hooping  was  visible." 


126  GEORGE  BIDDELL  AIRY. 

"  Previous  to  1836  I  had  begun  to  contemplate  the  attach- 
ment of  Magnetic  Observations  to  the  Observatory,  and  had 
corresponded  with  Prof.  Christie,  Prof.  Lloyd,  Prof.  J.  D. 
Forbes,  and  Mr  Gauss  on  the  subject.  On  Jan.  I2th  1836  I 
addressed  a  formal  letter  to  the  Admiralty,  and  on  Jan.  i8th 
received  their  answer  that  they  had  referred  it  to  the  Board 
of  Visitors.  On  March  25th  I  received  authority  for  the 
expenditure  of  £30,  and  I  believe  that  I  then  ordered  Merz's 
2-foot  magnet.  The  Visitors  met  on  Feb.  26th  and  after 
some  discussion  the  site  was  chosen  and  the  extent  of  ground 
generally  defined,  and  on  Dec.  22nd  Mr  Spring  Rice  (Lord 
Monteagle)  as  Chancellor  of  the  Exchequer  virtually  effected 
the  transfer  of  the  ground.  But  no  further  steps  were  taken 
in  1836.  A  letter  on  a  systematic  course  of  magnetic  obser- 
vations in  various  parts  of  the  world  was  addressed  by  Baron 
Alexander  Humboldt  to  the  Duke  of  Sussex,  President  of  the 
Royal  Society:  and  was  referred  to  Prof.  Christie  and  me. 
We  reported  on  it  on  June  gth  1836,  strongly  recommending 
the  adoption  of  the  scheme. 

"A  plan  had  been  proposed  by  the  Promoters  of  the 
London  and  Gravesend  Railway  (Col.  Landman,  Engineer) 
for  carrying  a  railway  at  high  level  across  the  bottom  of  the 
Park.  On  Jan.  Qth  I  received  orders  from  the  Admiralty  to 
examine  into  its  possible  effect  in  producing  vibrations  in  the 
Observatory.  After  much  correspondence,  examination  of 
ground,  &c.,  I  fixed  upon  a  part  of  the  Greenwich  Railway 
(not  yet  opened  for  traffic)  near  the  place  where  the  Croydon 
trunk  line  now  joins  it,  as  the  place  for  trains  to  run  upon, 
while  I  made  observations  with  a  telescope  viewing  a  col- 
limator  by  reflection  in  mercury  at  the  distance  of  500  feet. 
The  experiments  were  made  on  Jan.  25th,  and  I  reported  on 
Feb.  4th.  It  was  shewn  that  there  would  be  some  danger  to 
the  Observatory.  On  Nov.  2nd  Mr  James  Walker,  Engineer, 
brought  a  model  of  a  railway  to  pass  by  tunnel  under  the 
lower  part  of  the  Park  :  apparently  this  scheme  was  not 
pressed. 


AT  GREENWICH   OBSERVATORY. 


"  In  addition  to  the  routine  work  of  the  Observatory,  a 
special  set  of  observations  were  made  to  determine  the  mass 
of  Jupiter.  —  Also  the  Solar  Eclipse  of  May  I5th  was  observed 
at  Greenwich  in  the  manner  which  I  had  introduced  at  Cam- 
bridge. —  The  Ordnance  Zenith  Sector,  and  the  instruments  for 
the  St  Helena  Observatory  were  brought  for  examination.  — 
Much  attention  was  given  to  chronometers,  and  various  steps 
were  taken  for  their  improvement.  —  I  had  some  important 
correspondence  with  Mr  (Sir  John)  Lubbock,  upon  the  Lunar 
Theory  generally  and  his  proposed  empirical  lunar  tables. 
This  was  the  first  germ  of  the  great  reduction  of  Lunar 
Observations  which  I  subsequently  carried  out.  —  In  October 
I  was  nominated  on  the  Council  of  the  Royal  Society,  having 
been  admitted  a  Fellow  on  Feb.  i8th  1836.  I  was  President 
of  the  Astronomical  Society  during  this  and  the  preceding 
year  (1836  and  1835). 

"  My  connection  with  Groombridge's  Catalogue  of  Stars 
began  in  1832,  and  the  examination,  in  concert  with  Mr 
Baily,  of  the  edition  printed  by  Mr  Henry  Taylor,  resulted  in 
its  condemnation.  In  1834  I  volunteered  to  the  Admiralty 
to  prepare  a  new  edition,  and  received  their  thanks  and  their 
authority  for  proceeding.  It  required  a  great  deal  of  ex- 
amination of  details,  and  much  time  was  spent  on  it  in 
1836:  but  it  was  not  brought  to  the  state  of  readiness  for 
press. 

"My  predecessor,  Mr  Pond,  died  on  Sept.  7th  1836,  and 
was  interred  in  Halley's  tomb  in  Lee  churchyard." 


The  following  letter  was  written  by  Airy  in  support  of 
the  application  for  a  pension  to  Mrs  Pond,  who  had  been  left 
in  great  distress : 

To   HENRY   WARBURTON,   ESQ. 

"  The  points  upon  which  in  my  opinion  Mr  Pond's  claims  to  the 
gratitude  of  Astronomers  are  founded,  are  principally  the  following. 
First  and  chief,  the  accuracy  which  he  introduced  into  all  the  princi- 


128  GEORGE   BIDDELL  AIRY. 

pal  observations.  This  is  a  thing  which  from  its  nature  it  is  extremely 
difficult  to  estimate  now,  so  long  after  the  change  has  been  made, 
and  I  can  only  say  that  so  far  as  I  can  ascertain  from  books  the 
change  is  one  of  very  great  extent  j  for  certainty  and  accuracy, 
Astronomy  is  quite  a  different  thing- from  what  it  was,  and  this  is 
mainly  due  to  Mr  Pond.  The  most  striking  exemplification  of  this 
is  in  his  laborious  working  out  of  every  conceivable  cause  or  indica- 
tion of  error  in  the  Circle  and  the  two  Circles :  but  very  great  praise 
is  also  due  for  the  new  system  which  he  introduced  in  working  the 
Transit.  In  comparing  Mr  Pond's  systems  of  observation  with  Dr 
Maskelyne's,  no  one  can  avoid  being  impressed  with  the  inferiority 
of  Dr  Maskelyne's.  It  is  very  important  to  notice  that  the  conti- 
nental observatories  which  have  since  attracted  so  much  attention  did 
not  at  that  time  exist  or  did  not  exist  in  vigour.  Secondly ',  the  atten- 
tion bestowed  by  Mr  Pond  on  those  points  (chiefly  of  sidereal  astro- 
nomy) which  he  regarded  as  fundamental :  to  which  such  masses  of 
observations  were  directed  as  entirely  to  remove  the  doubts  from 
probable  error  of  individual  observations  or  chance  circumstances 
which  have  injured  many  other  determinations.  Thirdly ',  the  regu- 
larity of  observation.  The  effect  of  all  these  has  been  that,  since  the 
commencement  of  Mr  Pond's  residence  at  Greenwich,  Astronomy 
considered  as  an  accurate  representation  of  the  state  of  the  heavens 
in  the  most  material  points  has  acquired  a  certainty  and  an  extent 
which  it  never  had  before.  There  is  no  period  in  the  history  of  the 
science  so  clean.  On  some  matters  (in  regard  to  the  choice  of 
observations)  I  might  say  that  my  own  judgment  would  have  differed 
in  some  degree  from  Mr  Pond's,  but  one  thing  could  have  been 
gained  only  by  giving  up  another,  and  upon  the  general  accuracy  no 
improvement  could  have  been  made.  Mr  Pond  understood  nothing 
of  physical  astronomy ;  but  neither  did  anybody  else,  in  England. 

The  supposed  decrease  of  general  efficiency  in  the  last  few  years 
is  to  be  ascribed  to  the  following  causes : 

1.  Mr  Pond's  ill  health. 

2.  The  inefficiency  of  his  first  assistant. 

3.  The  oppression  of  business  connected  with  chronometers. 
The  last  of  these,  as  I  have  reason  to  think,  operated  very  far. 

Business  of  this  nature  which  (necessarily)  is  daily  and  peremptory 
will  always  prevail  over  that  which  is  general  and  confidential.  I  will 
not  trouble  you  with  an  account  of  the  various  ways  in  which  the 
chronometer  business  teazed  the  Astronomer  Royal  (several  altera- 
tions having  been  made  at  my  representation),  but  shall  merely 


AT  GREENWICH   OBSERVATORY.  129 

remark  that  much  of  the  business  had  no  connection  whatever  with 
astronomy. 

"  I  beg  to  submit  these  remarks  to  your  perusal,  requesting  you  to 
point  out  to  me  what  part  of  them  should  be  laid  before  any  of  the 
King's  Ministers,  at  what  time,  in  what  shape,  and  to  whom  addressed. 
I  am  quite  sure  that  Mrs  Pond's  claims  require  nothing  to  ensure 
favourable  consideration  but  the  impression  of  such  a  feeling  of  Mr 
Pond's  astronomical  merits  as  must  be  entertained  by  any  reasonable 
astronomer;  and  I  am  most  anxious  to  assist  in  conveying  this 
impression." 

"  Of  private  history  :  I  went  to  Suffolk  for  a  week  on  Mar. 
25th.  On  Sept.  igth  my  son  Wilfrid  (my  fourth  child)  was 
born.  In  October  I  made  an  excursion  for  a  week  round  the 
coast  of  Kent.  In  November  I  went  to  my  brother's  house 
at  Keysoe  in  Bedfordshire :  I  was  much  exposed  to  cold  on 
the  return-journey,  which  probably  aggravated  the  illness 
that  soon  followed.  From  Nov.  2/th  I  was  ill ;  made  the 
last  journal  entry  of  the  year  on  Dec.  6th ;  the  next  was  on 
Jan.  I4th,  1837.  I  find  that  in  this  year  I  had  introduced 
Arthur  Biddell  to  the  Tithe  Commutation  Office,  where  he 
was  soon  favourably  received,  and  from  which  connection  he 
obtained  very  profitable  employment  as  a  valuer/' 

1837 

"  My  connection  with  Cambridge  Observatory  was  not  yet 
finished.  I  had  determined  that  I  would  not  leave  a  figure 
to  be  computed  by  my  successor.  In  October  I  had  (at  my 
private  expense)  set  Mr  Glaisher  to  work  on  reducing  the 
observations  of  Sun,  Moon,  and  Planets  made  in  1833,  1834, 
1835;  and  subsequently  had  the  calculations  examined  by 
Mr  Hartnup.  This  employed  me  at  times  through  1837.  I 
state  here,  once  for  all,  that  every  calculation  or  other  work 
in  reference  to  the  Cambridge  Observatory,  in  this  and  sub- 
sequent years,  was  done  at  my  private  expense.  The  work 
of  the  Northumberland  Telescope  was  going  on  through  the 
year :  from  Nov.  24th  to  29th  I  was  at  Cambridge  on  these 
works. 

A.  B.  g 


130  GEORGE   BIDDELL   AIRY. 

"An  object-glass  of  6f  inches  aperture  (a  most  unusual 
size  at  this  time,  when  it  was  difficult  to  find  a  4-inch  or 
5 -inch  glass)  had  been  presented  to  the  Greenwich  Observa- 
tory by  my  friend  Mr  Sheepshanks,  and  on  Mar.  2Qth  I 
received  from  the  Admiralty  authority  for  mounting  it  equa- 
toreally  in  the  empty  South  Dome,  which  had  been  intended 
for  a  copy  of  the  Palermo  Circle. — In  the  month  of  July  the 
Admiralty  wished  for  my  political  assistance  in  a  Greenwich 
election,  but  I  refused  to  give  any. — On  Jan.  3rd  I  gave 
notice  to  the  Admiralty  that  I  had  finished  the  computations 
of  Groombridge's  Catalogue,  and  was  ready  to  print.  The 
printing  was  authorized  and  proceeded  (the  introduction 
was  finished  on  Nov.  22nd),  but  the  book  was  not  quite  ready 
till  the  beginning  of  1838. — In  connection  with  the  Cavendish 
experiment:  on  June  loth  I  wrote  to  Spring  Rice  (Chan- 
cellor of  the  Exchequer)  for  £500,  which  was  soon  granted : 
and  from  this  time  there  is  a  great  deal  of  correspondence 
(mainly  with  Mr  Baily)  upon  the  details  of  the  experiment 
and  the  theory  of  the  calculation. — On  July  24th  I  saw  the 
descent  of  the  parachute  by  which  Mr  Cocking  was  killed. 
I  attended  the  coroner's  inquest  and  gave  evidence  a  few 
days  later. 

"The  Planetary  Reductions  from  1750  to  1830  had  been 
going  on :  the  computers  (Glaisher,  Hartnup,  and  Thomas) 
worked  in  the  Octagon  Room,  and  considerable  advance  was 
made. — In  consequence  of  the  agitation  of  the  proposal  by 
Mr  Lubbock  to  form  empirical  tables  of  the  Moon,  for  which 
I  proposed  to  substitute  complete  reduction  of  the  observa- 
tions of  the  Moon  from  1750,  the  British  Association  at  York 
(Oct.  23rd,  1837)  appointed  a  deputation  (including  myself) 
to  place  the  matter  before  the  Government.  I  wrote  on  the 
matter  to  Mr  Wood  (Lord  Halifax)  stating  that  it  would  be 
proper  to  raise  the  First  Assistant's  salary,  and  to  give  me 
more  indefinite  power  about  employing  computers.  In  all 
these  things  I  received  cordial  assistance  from  Mr  Wood. 
The  Chancellor  of  the  Exchequer  (Mr  Spring  Rice)  received 


AT   GREENWICH   OBSERVATORY.  131 

us  on  Dec.  2Oth :  statements  were  furnished  by  me,  and  the 
business  was  sanctioned  immediately. — During  this  year  I 
was  very  much  engaged  in  correspondence  with  Lubbock 
and  others  on  improvements  of  the  Lunar  Theory. 

"In  the  operations  of  1836  and  1837  a  great  quantity  of 
papers  had  been  accumulated.  I  had  kept  them  in  reason- 
ably good  order,  tied  up  in  bundles :  but  this  method  began 
to  fail  in  convenience,  as  the  number  increased.  The  great 
lines  of  classification  were  however  now  well  understood.  I 
believe  it  was  in  the  latter  part  of  the  year  1837  that  I 
finally  settled  on  the  principle  of  arranging  papers  in  packets 
and  subordinate  packets,  every  paper  being  flat,  by  the  use 
of  four  punched  holes  in  every  paper.  I  have  never  seen  any 
principle  of  arrangement  comparable  to  this.  It  has  been 
adopted  with  the  greatest  ease  by  every  assistant,  and  is  used 
to  the  present  time  (1871)  without  alteration. 

"  On  Jan.  3rd  I  was  informed  unofficially  by  Mr  Wood 
(Admiralty  Secretary)  that  the  addition  of  the  Magnetic 
Ground  was  sanctioned.  On  Feb.  1 6th  Mr  Rhodes  (an 
officer  of  the  Department  of  Woods  and  Works)  came  to  put 
me  formally  in  possession  of  the  ground.  Between  Apr.  26th 
and  May  I3th  the  ground  was  enclosed,  and  my  garden  was 
completely  protected  from  the  public.  The  plan  of  the  build- 
ing was  settled,  and  numerous  experiments  were  made  on 
various  kinds  of  concrete  :  at  last  it  was  decided  to  build 
with  wood. 

"After  a  dinner  given  by  Lord  Burlington,  Chancellor, 
the  first  meeting  of  the  London  University  was  held  on 
Mar.  4th,  and  others  followed.  On  Apr.  i8th  I  handed  to 
the  Chancellor  a  written  protest  against  a  vote  of  a  salary  of 
£1000  to  the  Registrar:  which  salary,  in  fact,  the  Govern- 
ment refused  to  sanction.  Dissensions  on  the  question  of 
religious  examination  were  already  beginning,  but  I  took 
little  part  in  them. 

"  In  1833  Mr  Henderson  had  resigned  the  superintendance 
of  the  Cape  of  Good  Hope  Observatory,  and  Mr  Maclear 

9—2 


132  GEORGE   BIDDELL  AIRY. 

was  appointed.  I  recommended  the  same  Official  Instruc- 
tions for  him  (they  had  included  an  allusion  to  La  Caille's 
Arc  of  Meridian)  with  an  addition  on  the  probability  of 
Trigonometrical  Survey,  on  Aug*.  8th,  1837.  On  Feb.  24th, 
1837,  I  wrote  to  Beaufort  suggesting  that  Bradley's  Sector 
should  be  used  for  verifying  the  astronomical  determinations, 
and  subsequently  received  the  approval  of  the  Admiralty. 
In  June  Sir  J.  Herschel  and  I  had  an  interview  with  Mr 
Wood  on  the  Cape  equipment  generally.  The  Sector  was 
erected  with  its  new  mounting,  careful  drawings  were  made 
of  every  part,  instructions  were  prepared  for  its  use,  and  on 
Aug.  loth  it  was  sent  to  Woolwich  Dockyard  and  shipped 
for  the  Cape. 

"Of  private  history:  On  Aug.  23rd  I  started  with  my 
wife  for  an  excursion  in  South  Wales,  &c.  On  Sept.  Qth  I 
gave  a  lecture  in  the  Town  Hall  of  Neath.  While  at  Swansea 
we  received  news  of  the  death  of  my  wife's  father,  the  Rev. 
Richard  Smith,  and  returned  at  once. — In  this  year  Arthur 
Biddell  bought  the  little  Eye  estate  for  me." 

1838 

"Cambridge  Observatory :—  On  Dec.  29th,  1837,  I  had  set 
Mr  Glaisher  to  work  in  collecting  the  annual  results  for 
star-places  from  the  Cambridge  Observations,  to  form  one 
catalogue:  I  examined  the  calculations  and  the  deduced 
catalogue,  and  on  Dec.  14,  1838,  presented  it  to  the  Royal 
Astronomical  Society,  under  the  title  of  'The  First  Cam- 
bridge Catalogue.' — For  the  Northumberland  telescope  I  was 
engaged  with  Simms  about  the  clockwork  from  time  to  time 
up  to  Apr.  3Oth,  and  went  to  Cambridge  about  it.  The 
instrument  was  brought  to  a  useable  state,  but  some  small 
parts  were  still  wanting. 

"  At  Greenwich  : — In  April  I  drew  up  a  little  history  of 
the  Observatory  for  the  Penny  Cyclopaedia. — On  June  3Oth 
the  Lords  of  the  Admiralty  paid  a  short  visit  to  the  Observa- 


AT   GREENWICH   OBSERVATORY.  133 

tory  :  on  this  occasion  Mr  Wood  suggested  a  passage  con- 
necting the  Observatory  with  the  dwelling-house,  and  I 
subsequently  prepared  sketches  for  it;  it  was  made  in  the 
next  year. — In  the  course  of  the  year  the  Sheepshanks 
Equatoreal  was  mounted,  and  Encke's  Comet  was  observed 
with  it  from  Oct.  26th  to  Nov.  1 3th.— On  Mar.  3ist,  &c.  I 
reported  to  the  Admiralty  on  the  selection  of  chronometers 
for  purchase,  from  a  long  list :  this  was  an  important  begin- 
ning of  a  new  system. — The  Magnetic  Observatory  was  built, 
in  the  form  originally  planned  for  it  (a  four-armed  cross  with 
equal  arms,  one  axis  being  in  the  magnetic  meridian)  in  the 
beginning  of  this  year.  (No  alteration  has  since  been  made  in 
form  up  to  the  present  time,  1871,  except  that  the  north  arm 
has  been  lengthened  8  feet  a  few  years  ago.)  On  May  2ist  a 
magnet  was  suspended  for  the  first  time,  Mr  Baily  and  Lieut, 
(afterwards  Sir  William)  Denison  being  present. — Groom- 
bridge's  Catalogue  was  finished,  and  on  Mar.  3rd  I  arranged 
for  sending  out  copies. — The  Planetary  Reductions  were 
carried  on  vigorously.  On  May  3 1st,  1838,  the  Treasury 
assented  to  the  undertaking  of  the  Lunar  Reductions  and 
allotted  £2,000  for  it :  preparations  were  made,  and  in  the 
autumn  7  computers  were  employed  upon  it.  It  will  easily 
be  seen  that  this  undertaking  added  much  to  my  labours  and 
cares. — The  geodetic  afifairs  of  the  Cape  of  Good  Hope  began 
to  be  actively  pressed,  and  in  February  Beaufort  wrote  to  me 
in  consequence  of  an  application  from  Maclear,  asking  about 
a  standard  of  length  for  Maclear  (as  foundation  for  a  geodetic 
survey).  I  made  enquiries,  and  on  Mar.  I3th  wrote  to  Mr 
Wood,  alluding  also  generally  to  the  want  of  a  National 
English  standard  after  the  destruction  of  the  Houses  of 
Parliament.  On  Apr.  24th  the  Admiralty  sanctioned  my 
procuring  proper  Standard  Bars. — In  connection  with  the 
Cavendish  Experiment,  I  have  an  immense  quantity  of  corre- 
spondence with  Mr  Baily,  and  all  the  mathematics  were 
furnished  by  me:  the  experiment  was  not  finished  at  the  end 
of  the  year. — The  Perturbations  of  Uranus  were  now  attract- 


134  GEORGE   BIDDELL  AIRY. 

ing  attention.  I  had  had  some  correspondence  on  this  subject 
with  Dr  Hussey  in  1834,  and  in  1837  with  Eugene  Bouvard. 
On  Feb.  24th,  of  1838,  I  wrote  to  Schumacher  regarding  the 
error  in  the  tabular  radius-vector;"of  Uranus,  which  my  mode 
of  reducing  the  observations  enabled  me  to  see. 

"  The  National  Standards  of  Length  and  Weight  had  been 
destroyed  in  the  fire  of  the  Houses  of  Parliament.  On  May 
nth  I  received  a  letter  from  Mr  Spring  Rice,  requesting  me 
to  act  (as  chairman)  with  a  committee  consisting  of  F.  Baily, 
J.  E.  Drinkwater  Bethune,  Davies  Gilbert,  J.  G.  S.  Lefevre, 
J.  W.  Lubbock,  G.  Peacock,  and  R.  Sheepshanks,  to  report 
on  the  steps  now  to  be  taken.  I  accepted  the  charge,  and  the 
first  meeting  was  held  at  the  Observatory  on  May  22nd ;  all 
subsequent  meetings  in  London,  usually  in  the  apartments  of 
the  Royal  Astronomical  Society.  I  acted  both  as  chairman 
and  as  working  secretary.  Our  enquiries  went  into  a  very 
wide  field,  and  I  had  much  correspondence. 

"On  Jan.  4th  Mr  Wood  wrote  to  me,  mentioning  that 
Capt.  Johnson  had  made  some  observations  on  the  magnetism 
of  iron  ships,  and  asking  whether  they  ought  to  be  continued  ; 
a  steamer  being  offered  at  £50  per  week.  I  applied  to  Beau- 
fort for  a  copy  of  Johnson's  Observations,  and  on  Jan.  7th 
replied  very  fully,  discouraging  such  observations  ;  but  recom- 
mending a  train  of  observations  expressly  directed  to  theo- 
retical points.  On  Feb.  I7th  I  reported  that  I  had  examined 
the  Deptford  Basin,  and  found  that  it  would  do  fairly  well  for 
experiments.  On  July  I4th,  1838,  Capt.  Beaufort  wrote  to  me 
that  the  Admiralty  wished  for  experiments  on  the  ship,  the 
'  Rainbow,'  then  in  the  river,  and  enquired  whether  I  would 
undertake  them  and  what  assistance  I  desired,  as  for  instance 
that  of  Christie  or  Barlow.  I  replied  that  one  person  should 
undertake  it,  either  Christie,  Barlow,  or  myself,  and  that  a 
basin  was  desirable.  On  July  i6th  and  I7th  I  looked  at  the 
basins  of  Woolwich  and  Deptford,  approving  the  latter.  On 
July  2  ist  the  Admiralty  gave  me  full  powers.  From  July  23rd 
I  was  almost  entirely  employed  on  preparations.  The  course 


AT  GREENWICH   OBSERVATORY.  135 

of  operations  is  described  in  my  printed  Paper :  the  original 
maps,  curves,  and  graphical  projections,  are  in  the  bound 
MSS. :  '  Correction  of  Compass  in  Iron  Ships — "  Rainbow,"  '  at 
the  Greenwich  Observatory.  The  angular  disturbances  were 
found  on  July  26th  and  3Oth,  requiring  some  further  work  on 
a  raft,  so  that  they  were  finally  worked  out  on  Aug.  nth.  I 
struggled  hard  with  the  numbers,  but  should  not  have  suc- 
ceeded if  it  had  not  occurred  to  me  to  examine  the  horizontal 
magnetic  intensities.  This  was  done  on  Aug.  I4th,  and  the 
explanation  of  the  whole  was  suggested  at  once :  graphical 
projections  were  made  on  Aug.  i6th  and  I7th  for  comparison 
of  my  explanation  with  observations,  and  the  business  was 
complete.  On  Aug.  I7th  and  i8th  I  measured  the  intensity 
of  some  magnets,  to  be  used  in  the  ship  for  correction.  It  is 
to  be  remarked  that,  besides  the  effect  of  polar  magnetism, 
there  was  no  doubt  of  the  existence  of  an  effect  of  induced 
magnetism  requiring  correction  by  other  induced  magnetism  : 
and  experiments  for  this  were  made  in  the  Magnetic  Obser- 
vatory. All  was  ready  for  trial :  and  on  Aug.  2oth  I  carried 
my  magnets  and  iron  correctors  to  Deptford,  mounted  them 
in  the  proper  places,  tried  the  ship,  and  the  compass,  which 
had  been  disturbed  50  degrees  to  the  right  and  50  degrees  to 
the  left,  was  now  sensibly  correct.  On  Aug.  2ist  I  reported 
this  to  the  Admiralty,  and  on  Aug.  24th  I  tried  the  ship  to 
Gravesend.  On  Aug.  3Oth  I  had  the  loan  of  her  for  an  ex- 
pedition with  a  party  of  friends  to  Sheerness,  and  on  Sept.  9th 
I  accompanied  her  to  Gravesend,  on  her  first  voyage  to  Ant- 
werp.— On  Oct.  5th  application  was  made  to  me  by  the  owner 
of  the  *  Ironsides '  to  correct  her  compasses.  In  consequence 
of  this  I  went  to  Liverpool  on  Oct.  25th,  and  on  this  occasion 
made  a  very  important  improvement  in  the  practical  mode  of 
performing  the  correction. — On  Nov.  i6th  I  reported  to  the 
Admiralty  in  considerable  detail.  On  Dec.  4th  I  had  an 
interview  with  Lord  Minto  (First  Lord  of  the  Admiralty)  and 
Mr  Wood.  They  refused  to  sanction  any  reward  to  me. — 
The  following  is  a  copy  of  the  report  of  the  Captain  of  the 


136  GEORGE   BIDDELL  AIRY. 

'  Rainbow '  after  her  voyage  to  Antwerp :  '  Having  had  the 
command  of  the  Rainbow  steamer  the  two  voyages  between 
London  and  Antwerp,  I  have  the  pleasure  to  inform  you  that 
I  am  perfectly  satisfied  as  to  the  Correctness  of  the  compasses, 
and  feel  quite  certain  they  will  continue  so.  I  took  particular 
notice  from  land  to  land  from  our  departure  and  found  the 
bearings  by  compass  to  be  exact.'" — The  following  extracts 
from  letters  to  his  wife  refer  to  the  "  Ironsides  " :  on  Oct.  28th 
1838  he  writes,  "  I  worked  up  the  observations  so  much  as  to 
see  that  the  compass  disturbance  is  not  so  great  as  in  the 
'Rainbow'  (35°  instead  of  50°),  but  quite  enough  to  make 
the  vessel  worthless ;  and  that  it  is  quite  different  in  direction 
from  that  in  the  '  Rainbow ' — so  that  if  they  had  stolen  one 
of  the  '  Rainbow  '  correctors  and  put  it  into  this  ship  it  would 
have  been  much  worse  than  before."  And  on  Nov.  ist  he 
writes,  "  On  Wednesday  I  again  went  to  the  ship  and  tried 
small  alterations  in  the  correctors :  I  am  confident  now  that 
the  thing  is  very  near,  but  we  were  most  abominably  baffled 
by  the  sluggishness  of  the  compass." 

"  The  University  of  London  : — On  Jan.  6th  I  attended  a 
sub-committee  meeting  on  the  minimum  of  acquirements  for 
B.A.  degree,  and  various  meetings  of  the  Senate.  On  July 
1 4th  I  intimated  to  Mr  Spring  Rice  my  wish  to  resign.  I 
had  various  correspondence,  especially  with  Mr  Lubbock,  and 
on  Dec.  I3th  I  wrote  to  him  on  the  necessity  of  stipends  to 
Members  of  Senate.  The  dissensions  on  religious  examina- 
tion became  very  strong.  I  took  a  middle  course,  demanding 
examination  in  the  languages  and  books,  but  absolutely  re- 
fusing to  claim  any  religious  assent.  I  expressed  this  to  Dr 
Jerrard,  the  principal  representative  on  the  religious  side,  by 
calling  on  him  to  substitute  the  words  '  Recognition  of  Chris- 
tian Literature '  for  '  Recognition  of  Christian  Religion ' :  I 
addressed  a  printed  letter  to  Lord  Burlington  (Chancellor) 
and  the  Members  of  the  Senate,  on  this  subject. 

"  Of  private  history :  In  January  I  made  a  short  excur- 
sion in  Norfolk  and  Suffolk,  and  visited  Prof.  Sedgwick  at 


AT   GREENWICH   OBSERVATORY.  137 

Norwich.  In  April  I  paid  a  short  visit  to  Mr  Courtney  at 
Sanderstead,  with  my  wife.  On  June  I4th  my  son  Hubert 
was  born.  In  September  I  went  with  my  sister  by  Cam- 
bridge, &c.,  to  Luddington,  where  I  made  much  enquiry 
concerning  my  father  and  the  family  of  Airy  who  had  long 
been  settled  there.  We  then  visited  various  places  in  York- 
shire, and  arrived  at  Brampton,  near  Chesterfield,  where  Mrs 
Smith,  my  wife's  mother,  now  resided.  And  returned  by 
Rugby.  I  had  much  correspondence  with  my  brother  and 
for  him  about  private  pupils  and  a  better  church  living. 
I  complained  to  the  Bishop  of  Norwich  about  the  mutilation 
of  a  celebrated  monument  in  Playford  Church  by  the  incum- 
bent and  curate." 

The  following  extracts  are  from  letters  to  his  wife  relating 
to  the  above-mentioned  journeys : 

CLOSE,  NORWICH. 

1838,  Jan.  21. 

I  do  not  know  what  degree  of  cold  you  may  have  had  last  night, 
but  here  it  was  (I  believe)  colder  than  before — thermometer  close  to 
the  house  at  3°.  I  have  not  suffered  at  all.  However  I  do  not 
intend  to  go  to  Lowestoft. 

BRAMPTON. 

1838,  Sept.  30th. 

We  began  to  think  that  we  had  seen  enough  of  Scarborough,  so 
we  took  a  chaise  in  the  afternoon  to  Pickering,  a  small  agricultural 
town,  and  lodged  in  a  comfortable  inn  there.  On  Wednesday  morn- 
ing at  8  we  started  by  the  railroad  for  Whitby,  in  a  huge  carriage 
denominated  the  Lady  Hilda  capable  of  containing  40  persons  or 
more  drawn  by  one  horse,  or  in  the  steep  parts  of  the  railway  by  two 
horses.  The  road  goes  through  a  set  of  defiles  of  the  eastern  moor- 
lands of  Yorkshire  which  are  extremely  pretty :  at  first  woody  and 
rich,  then  gradually  poorer,  and  at  last  opening  on  a  black  moor  with 
higher  moors  in  sight :  descending  in  one  part  by  a  long  crooked 
inclined  plane,  the  carriage  drawing  up  another  load  by  its  weight : 
through  a  little  tunnel :  and  then  along  a  valley  to  Whitby.  The 
rate  of  travelling  was  about  10  miles  an  hour.  Betsy  declares  that  it 
was  the  most  agreeable  travelling  that  she  ever  had. 


138  GEORGE   BIDDELL   AIRY. 

Yesterday  (Saturday)  Caroline  drove  Betsy  and  Miss  Barnes 
drove  me  to  Clay  Cross  to  see  the  works  at  the  great  railroad  tunnel 
there.  Coming  from  the  north,  the  railroad  passes  up  the  Chester- 
field valley  close  by  the  town,  and  continues  up  the  same  valley,  till 
it  is  necessary  for  it  to  enter  the  valley  which  runs  the  opposite  way 
towards  Buttersley  :  the  tunnel  passes  under  the  high  ground  between 
these  two  vallies  :  so  that  it  is  in  reality  at  the  water-shed  :  it  is  to  be 
I  think  more  than  a  mile  long,  and  when  finished  27  feet  clear  in 
height,  so  it  is  a  grand  place.  We  saw  the  preparations  for  a  blast, 
and  heard  it  fired  :  the  ladies  stopping  their  ears  in  due  form. 


1839 

"  Cambridge  Observatory : — On  Mar.  7th  I  went  to  Cam- 
bridge on  the  business  of  the  Northumberland  Telescope  :  I 
was  subsequently  engaged  on  the  accounts,  and  on  Aug.  i6th 
I  finally  resigned  it  to  Prof.  Challis,  who  accepted  it  on 
Aug.  i pth.  On  Sept.  nth  I  communicated  its  completion 
and  the  settlement  of  accounts  to  the  Duke  of  Northumber- 
land. The  total  expense  was  £1938.  gs.  2d.+  15000  francs 
for  the  object-glass. 

"  At  Greenwich  Observatory  : — On  Jan.  3rd  I  received  the 
last  revise  of  the  1837  Observations,  and  on  Jan.  8th  the  first 
sheet  for  1838. — In  July  I  report  on  selection  from  a  long  list 
of  chronometers  which  had  been  on  trial,  and  on  Sept.  2nd  I 
pointed  out  to  Capt  Beaufort  that  the  system  of  offering  only 
one  price  would  be  ruinous  to  the  manufacture  of  chrono- 
meters, and  to  the  character  of  those  supplied  to  the  Admir- 
alty :  and  that  I  would  undertake  any  trouble  of  classifying 
the  chronometers  tried.  This  letter  introduced  the  system 
still  in  use  (1871),  which  has  been  most  beneficial  to  the 
manufacture.  On  Sept.  nth  I  proposed  that  all  trials  begin 
in  the  first  week  of  January:  this  also  has  been  in  use  as  an 
established  system  to  the  present  time. — It  was  pointed  out 
to  me  that  a  certain  chronometer  was  affected  by  external 
magnetic  power.  I  remedied  this  by  placing  under  it  a  free 
compass  magnet :  a  stand  was  specially  prepared  for  it.  I 


AT   GREENWICH   OBSERVATORY.  139 

have  never  found  another  chronometer  sensibly  affected 
by  magnetism. — In  November  and  December  I  tried  my  new 
double-image  micrometer. — Between  May  i6th  and  Oct.  I3th 
a  fireproof  room  was  constructed  in  the  southern  part  of  the 
quadrant  room  ;  and  in  November  a  small  shed  was  erected 
over  the  entrance  to  the  North  Terrace. — The  position  of  the 
free  Meridional  Magnet  (now  mounted  in  the  Magnetic 
Observatory)  was  observed  at  every  5  m.  through  24  hours 
on  Feb.  22nd  and  23rd,  May  24th  and  25th,  Aug.  3<Dth 
and  3  ist,  and  Nov.  29th  and  3Oth.  This  was  done  in  co- 
operation with  the  system  of  the  Magnetic  Union  estab- 
lished by  Gauss  in  Germany. — The  Reduction  of  the 
Greenwich  Planetary  and  Lunar  Observations,  1750  to 
1830,  went  on  steadily.  I  had  six  and  sometimes  seven 
computers  constantly  at  work,  in  the  Octagon  Room. — As 
in  1838  I  had  a  great  amount  of  correspondence  with  Mr 
Baily  on  the  Cavendish  Experiment. — I  attended  as  regu- 
larly as  I  could  to  the  business  of  the  University  of  London. 
The  religious  question  did  not  rise  very  prominently.  I  took 
a  very  active  part,  and  have  a  great  deal  of  correspondence, 
on  the  nature  of  the  intended  examinations  in  Hydrography 
and  Civil  Engineering. — On  the  Standards  Commission  the 
chief  work  was  in  external  enquiries. — On  June  6th  I  had 
enquiries  from  John  Quincey  Adams  (U.  S.  A.)  on  the 
expense,  &c.,  of  observatories :  an  observatory  was  contem- 
plated in  America. — I  had  correspondence  about  the  proposed 
establishment  of  observatories  at  Durham,  Glasgow,  and  Liver- 
pool. 

"  I  had  in  this  year  a  great  deal  of  troublesome  and  on  the 
whole  unpleasant  correspondence  with  the  Admiralty  about 
the  correction  of  the  compass  in  iron  ships.  I  naturally  ex- 
pected some  acknowledgment  of  an  important  service  rendered 
to  Navigation  :  but  the  Admiralty  peremptorily  refused  it. 
My  account  of  the  Experiments  &c.  for  the  Royal  Society 
is  dated  April  9th.  The  general  success  of  the  undertaking 
soon  became  notorious,  and  (as  I  understood)  led  immediately 


140  GEORGE   BIDDELL  AIRY. 

to  extensive  building  of  iron  ships :  and  it  led  also  to  applica- 
tions to  me  for  correction  of  compasses.  On  Jan.  Qth  I  was 
addressed  in  reference  to  the  Royal  Sovereign  and  Royal 
George  at  Liverpool;  July  i8th  tfee  Orwell;  May  nth  two 
Russian  ships  built  on  the  Thames  ;  Sept.  4th  the  ships  of 
the  Lancaster  Company. 

"I  had  much  work  in  connection  with  the  Cape  of  Good 
Hope  Observatory,  chiefly  relating  to  the  instrumental  equip- 
ment and  to  the  geodetical  work.  As  it  was  considered  advis- 
able that  any  base  measured  in  the  Cape  Colony  should  be 
measured  with  compensation  bars,  I  applied  to  Major  Jervis 
for  the  loan  of  those  belonging  to  the  East  Indian  Survey, 
but  he  positively  refused  to  lend  them.  On  Jan.  2Oth  I 
applied  to  Col.  Colby  for  the  compensation  bars  of  the 
British  Survey,  and  he  immediately  assented  to  lending 
them.  Col.  Colby  had  suggested  to  the  Ordnance  Depart- 
ment that  Capt.  Henderson  and  several  sappers  should  be 
sent  to  use  the  measuring  bars,  and  it  was  so  arranged. 
It  still  appeared  desirable  to  have  the  command  of  some 
soldiers  from  the  Garrison  of  Cape  Town,  and  this  matter 
was  soon  arranged  with  the  military  authorities  by  the 
Admiralty. 

"  The  following  are  the  principal  points  of  my  private 
history :  it  was  a  very  sad  year.  On  Jan.  24th  I  went  with 
my  wife  to  Norwich,  on  a  visit  to  Prof.  Sedgwick,  and  in 
June  I  visited  Sir  J.  Herschel  at  Slough.  On  June  I3th  my 
dear  boy  Arthur  was  taken  ill :  his  malady  soon  proved  to  be 
scarlet  fever,  of  which  hexiied  on  June  24th  at  7  in  the  morn-- 
ing. It  was  arranged  that  he  should  be  buried  in  Playford 
churchyard  on  the  28th,  and  on  that  day  I  proceeded  to 
Playford  with  my  wife  and  my  eldest  son  George  Richard. 
At  Chelmsford  my  son  was  attacked  with  slight  sickness,  and 
being  a  little  unwell  did  not  attend  his  brother's  funeral.  On 
July  ist  at  4h.  15  m.  in  the  morning  he  also  died  :  he  had 
some  time  before  suffered  severely  from  an  attack  of  measles, 
and  it  seemed  probable  that  his  brain  had  suffered.  On  July 


AT  GREENWICH   OBSERVATORY.  141 

5th  he  was  buried  by  the  side  of  his  brother  Arthur  in  Play- 
ford  churchyard. — On  July  23rd  I  went  to  Colchester  on  my 
way  to  Walton-on-the-Naze,  with  my  wife  and  all  my  family  ; 
all  my  children  had  been  touched,  though  very  lightly,  with 
the  scarlet  fever. — It  was  near  the  end  of  this  year  that  my 
mother  quitted  the  house  (Luck's)  at  Playford,  and  came  to 
live  with  me  at  Greenwich  Observatory,  where  she  lived  till 
her  death  ;  having  her  own  attendant,  and  living  in  perfect 
confidence  with  my  wife  and  myself,  and  being  I  trust  as 
happy  as  her  years  and  widowhood  permitted.  My  sister 
also  lived  with  me  at  the  Observatory." 

1840 

"  In  the  latter  part  of  1839,  and  through  1840,  I  had  much 
correspondence  with  the  Admiralty,  in  which  I  obtained  a 
complete  account  of  the  transfer  of  the  Observatory  from  the 
Ordnance  Department  to  the  Admiralty,  and  the  transfer  of 
the  Visitation  of  the  Observatory  from  the  Royal  Society  to 
the  present  Board  of  Visitors.  In  1840  I  found  that  the 
papers  of  the  Board  of  Longitude  were  divided  between  the 
Royal  Society  and  the  Admiralty :  I  obtained  the  consent  of 
both  to  bring  them  to  the  Observatory. 

"  In  this  year  I  began  to  arrange  about  an  annual  dinner 
to  be  held  at  the  Visitation. — My  double-image  micrometer 
was  much  used  for  observations  of  circumpolar  double  stars. 
— In  Magnetism  and  Meteorology,  certain  quarterly  observa- 
tions were  kept  up ;  but  in  November  the  system  of  incessant 
eye-observations  was  commenced.  I  refused  to  commence 
this  until  I  had  secured  a  '  Watchman's  Clock '  for  mechan- 
ical verification  of  the  regular  attendance  of  the  Assistants. — 
With  regard  to  chronometers :  In  this  year,  for  the  first  time, 
I  took  the  very  important  step  of  publishing  the  rates  ob- 
tained by  comparisons  at  the  Observatory.  I  confined  myself 
on  this  occasion  to  the  chronometers  purchased  by  the 
Admiralty.  In  March  a  pigeon-house  was  made  for  expo- 


142  GEORGE   BIDDELL  AIRY. 

sure  of  chronometers  to  cold. — The  Lunar  and  Planetary 
Reductions  were  going  on  steadily. — I  was  consulted  about 
an  Observatory  at  Oxford,  where  I  supported  the  introduc- 
tion of  the  Heliometer.— -The  stipend  of  the  Bakerian  Lec- 
ture was  paid  to  me  for  my  explanation  of  Brewster's  new 
prismatic  fringes. — The  business  of  the  Cape  Observatory 
and  Survey  occupied  much  of  my  time. — In  1838  the  Rev. 
H.  J.  Rose  (Editor  of  the  Encyclopaedia  Metropolitana)  had 
proposed  my  writing  a  Paper  on  Tides,  &c. ;  in  Oct.  1840  I 
gave  him  notice  that  I  must  connect  Tides  with  Waves,  and 
in  that  way  I  will  take  up  the  subject.  Much  correspondence 
on  Tides,  &c.,  with  Whewell  and  others  followed. 

"With  regard  to  the  Magnetical  and  Meteorological  Es- 
tablishment. On  June  i8th  Mr  Lubbock  reported  from  the 
Committee  of  Physics  of  the  Royal  Society  to  the  Council  in 
favour  of  a  Magnetic  and  Meteorological  Observatory  near 
London.  After  correspondence  with  Sheepshanks,  Lord 
Northampton,  and  Herschel,  I  wrote  to  the  Council  on  July 
9th,  pointing  out  what  the  Admiralty  had  done  at  Greenwich, 
and  offering  to  cooperate.  In  a  letter  to  Lord  Minto  I  stated 
that  my  estimate  was  £550,  including  ;£ioo  to  the  First 
Assistant:  Lubbock's  was  ^"3,000.  On  Aug.  nth  the  Treasury 
assented,  limiting  it  to  the  duration  of  Ross's  voyage.  On 
Aug.  1 7th  Wheatstone  looked  at  our  buildings  and  was  satis- 
fied. My  estimate  was  sent  to  the  Admiralty,  viz.  £150 
outfit,  £520  annual  expense ;  and  Glaisher  to  be  Superin- 
tendent. I  believe  this  was  allowed  for  the  present ;  for  the 
following  year  it  was  placed  on  the  Estimates.  Most  of  the 
contemplated  observations  were  begun  before  the  end  of 
1840:  as  much  as  possible  in  conformity  with  the  Royal 
Society's  plan.  Mr  Hind  (subsequently  the  Superintendent 
of  the  Nautical  Almanac)  and  Mr  Paul  were  the  first  extra 
assistants. 

"  Of  private  history.  On  Feb.  2Qth  I  went  to  Cambridge 
with  my  Paper  on  the  Going  Fusee.  On  Mar.  27th  I  went 
to  visit  Mrs  Smith,  my  wife's  mother,  at  Brampton  near 


AT   GREENWICH   OBSERVATORY.  143 

Chesterfield.  I  made  a  short  visit  to  Playford  in  April  and 
a  short  expedition  to  Winchester,  Portsmouth,  &c.,  in  June. 
From  Sept.  5th  to  Oct.  3rd  I  was  travelling  in  the  North  of 
England  and  South  of  Scotland."  [This  was  an  extremely 
active  and  interesting  journey,  in  the  course  of  which  a  great 
number  of  places  were  visited  by  Airy,  especially  places  on 
the  Border  mentioned  in  Scott's  Poems,  which  always  had  a 
great  attraction  for  him.  He  also  attended  a  Meeting  of  the 
British  Association  at  Glasgow  and  made  a  statement  regard- 
ing the  Planetary  and  Lunar  Reductions  :  and  looked  at  a  site 
for  the  Glasgow  Observatory.]  "  In  November  I  went  for  a 
short  time  to  Cambridge  and  to  Keysoe  (my  brother's  resi- 
dence). On  Dec.  26th  my  daughter  Hilda  was  born  (subse- 
quently married  to  E.  J.  Routh).  In  this  year  I  had  a  Ipss  of 
£3 5°  by  a  fife  on  mv  Eye  estate." 


The  following  extracts  are  from  letters  to  his  wife.  Some 
of  them  relate  to  matters  of  general  interest.  They  are  all 
of  them  characteristic,  and  serve  to  shew  the  keen  interest 
which  he  took  in  matters  around  him,  and  especially  in  archi- 
tecture and  scenery.  The  first  letter  relates  to  his  journey 
from  Chesterfield  on  the  previous  day. 

FLAMSTEED  HOUSE, 

1840,  April  2. 

I  was  obliged  to  put  up  with  an  outside  place  to  Derby  yester- 
day, much  against  my  will,  for  I  was  apprehensive  that  the  cold 
would  bring  on  the  pain  in  my  face.  Of  that  I  had  not  much ;  but 
I  have  caught  something  of  sore  throat  and  catarrh.  The  coach 
came  up  at  about  22  minutes  past  8.  It  arrived  in  Derby  at  20  minutes 
or  less  past  u  (same  guard  and  coachman  who  brought  us),  and 
drew  up  in  the  street  opposite  the  inn  at  which  we  got  no  dinner, 
abreast  of  an  omnibus.  I  had  to  go  to  a  coach  office  opposite  the 
inn  to  pay  and  be  booked  for  London,  and  was  duly  set  down  in  a 
way-bill  with  name;  and  then  entered  the  omnibus:  was  transferred 
to  the  Railway  Station,  and  then  received  the  Railway  Ticket  by 
shouting  out  my  name.  If  you  should  come  the  same  way,  you 


144  GEORGE   BIDDELL  AIRY. 

would  find  it  convenient  to  book  your  place  at  Chesterfield  to 
London  by  your  name  (paying  for  the  whole,  namely,  coach  fare, 
omnibus  fare  -/6,  and  railway  fare  £i.  15^.  od.  first  class).  Then 
you  will  only  have  to  step  out  .of  the  co,ach  into  the  omnibus,  and  to 
scream  out  once  or  twice  to  the  guard  to  make  sure  that  you  are 
entered  in  the  way-bill  and  that  your  luggage  is  put  on  the  omnibus. 


FLAMSTEED  HOUSE,  GREENWICH, 
1840,  April  15. 

I  forgot  to  tell  you  that  at  Lord  Northampton's  I  saw  some 
specimens  of  the  Daguerrotype,  pictures  made  by  the  Camera 
Obscura,  and  they  surpass  in  beauty  of  execution  anything  that  I 
could  have  imagined.  Baily  who  has  two  or  three  has  promised  to 
lend  them  for  your  inspection  when  you  return.  Also  I  saw  some 
post-office  stamps  and  stamped  envelopes :  I  do  not  much  admire 
the  latter. 


The  following  relates  to  the  fire  on  his  Eye  farm,  referred 
to  above : 

PLAYFORD, 

1840,  April  23. 

On  Wednesday  (yesterday)  went  with  my  uncle  to  the  Eye 
Estate,  to  see  the  effects  of  the  fire.  The  farming  buildings  of  every 
kind  are  as  completely  cleared -away  as  if  they  had  been  mown  down: 
not  a  bit  of  anything  but  one  or  two  short  brick  walls  and  the  brick 
foundations  of  the  barns  and  stacks.  The  aspect  of  the  place  is 
much  changed,  because  in  approaching  the  house  you  do  not  see  it 
upon  a  back-ground  of  barns,  &c.,  but  standing  alone.  The  house 
is  in  particularly  neat  and  good  order.  I  did  not  think  it  at  all 
worth  while  to  make  troublesome  enquiries  of  the  people  who  reside 
there,  but  took  Mr  Case's  account.  There  seems  no  doubt  that  the 
fire  was  caused  by  the  maid-servant  throwing  cinders  into  a  sort  of 
muck-place  into  which  they  had  been  commonly  thrown.  I  suppose 
there  was  after  all  this  dry  weather  straw  or  muck  drier  than  usual, 
and  the  cinders  were  hotter  than  usual.  The  whole  was  on  fire  in 
an  exceedingly  short  time ;  and  everything  was  down  in  less  than  an 
hour.  Two  engines  came  from  Eye,  and  all  the  population  of  the 


AT  GREENWICH   OBSERVATORY.  145 

town  (as  the  fire  began  shortly  after  two  o'clock  in  the  afternoon). 
It  is  entirely  owing  to  these  that  my  house,  and  the  farm  (SewelPs) 
on  the  opposite  side  of  the  road,  were  not  burned  down.  At  the 
beginning  of  the  fire  the  wind  was  N.E.  which  blew  directly  towards 
the  opposite  farm  (Sewell's) :  although  the  nearest  part  of  it  (tiled 
dwelling  house)  was  100  yards  off  or  near  it,  and  the  great  barn 
(thatched  roof)  considerably  further,  yet  both  were  set  on  fire  several 
times.  All  this  while,  the  tail  of  my  house  was  growing  very  hot : 
and  shortly  after  the  buildings  fell  in  burning  ruins,  the  wind  changed 
to  N.W.,  blowing  directly  to  my  house.  If  this  change  had  happened 
while  the  buildings  were  standing  and  burning,  there  would  have 
been  no  possibility  of  saving  the  house.  As  it  was,  the  solder  is 
melted  from  the  window  next  the  farm-yard,  and  the  roof  was  set  on 
fire  in  three  or  four  places.  One  engine  was  kept  working  on  my 
house  and  one  on  the  opposite  farm.  A  large  pond  was  pretty 
nearly  emptied.  Mr  Case's  horses  and  bullocks  were  got  out,  not 
without  great  difficulty,  as  the  progress  of  the  fire  was  fearfully  rapid. 
A  sow  and  nine  pigs  were  burnt,  and  a  large  hog  ran  out  burnt  so 
much  that  the  people  killed  it  immediately. 


GEORGE  INN,  WINCHESTER, 
1840,  June  21. 

At  Winchester  we  established  ourselves  at  the  George  and  then 
without  delay  proceeded  to  St  Cross.  I  did  not  know  before  the 
nature  of  its  hospital  establishment,  but  I  find  that  it  is  a  veritable 
set  of  alms-houses.  The  church  is  a  most  curious  specimen  of  the 
latest  Norman.  I  never  saw  one  so  well  marked  before— Norman 
ornaments  on  pointed  arches,  pilasters  detached  with  cushion  capitals, 
and  various  signs :  and  it  is  clearly  an  instance  of  that  state  of  the 
style  when  people  had  been  forced  by  the  difficulties  and  inelegan- 
cies  of  the  round  arch  in  groining  to  adopt  pointed  arches  for  groin- 
ing but  had  not  learnt  to  use  them  for  windows This  morning 

after  breakfast  went  to  the  Cathedral  (looking  by  the  way  at  a 
curious  old  cross  in  the  street).  I  thought  that  its  inside  was  wholly 
Norman,  and  was  most  agreeably  surprised  by  finding  the  whole 
inside  groined  in  every  part  with  excellent  late  decorated  or  perpen- 
dicular work.  Yet  there  are  several  signs  about  it  which  lead  me  to 
think  that  the  whole  inside  has  been  Norman,  and  even  that  the 
pilasters  now  worked  up  into  the  perpendicular  are  Norman.  The 
transepts  are  most  massive  old  Norman,  with  side-aisles  running 

A.  B.  10 


146  GEORGE   BIDDELL  AIRY. 

round  their  ends  (which  I  never  saw  before).  The  groining  of  the 
side  aisles  of  the  nave  very  effective  from  the  strength  of  the  cross 
ribs.  The  clerestory  windows  of  the  quire  very  large.  The  organ  is 
on  one  side.  But  the  best  thing  ..&bout  the  quire  is  the  wooden 
stall-work,  of  early  decorated,  very  beautiful.  A  superb  Lady  Chapel, 
of  early  English. 


PORTSMOUTH, 

1840,  June  23. 

We  left  Winchester  by  evening  train  to  the  Dolphin,  Southamp- 
ton, and  slept  there.  At  nine  in  the  morning  we  went  by  steamboat 
down  the  river  to  Ryde  in  the  Isle  of  Wight :  our  steamer  was  going 
on  to  Portsmouth,  but  we  thought  it  better  to  land  at  Ryde  and  take 
a  boat  for  ourselves.  We  then  sailed  out  (rather  a  blowing  day)  to 
the  vessel  attending  Col.  Pasley's  operations,  and  after  a  good  deal 
of  going  from  one  boat  to  another  (the  sea  being  so  rough  that  our 
boat  could  not  be  got  up  to  the  ships)  and  a  good  deal  of  waiting, 
we  got  on  board  the  barge  or  lump  in  which  Col.  Pasley  was.  Here 
we  had  the  satisfaction  of  seeing  the  barrel  of  gunpowder  lowered 
(there  was  more  than  a  ton  of  gunpowder),  and  seeing  the  divers  go 
down  to  fix  it,  dressed  in  their  diving  helmets  and  supplied  with  air 
from  the  great  air-pump  above.  When  all  was  ready  and  the  divers 
had  ascended  again,  the  barge  in  which  we  were  was  warped  away, 
and  by  a  galvanic  battery  in  another  barge  (which  we  had  seen 
carried  there,  and  whose  connection  with  the  barrel  we  had  seen), 
upon  signal  given  by  sound  of  trumpet,  the  gunpowder  was  fired. 
The  effect  was  most  wonderful.  The  firing  followed  the  signal 
instantaneously.  We  were  at  between  100  and  200  yards  from  the 
place  (as  I  judge),  and  the  effects  were  as  follows.  As  soon  as  the 
signal  was  given,  there  was  a  report,  louder  than  a  musket  but  not  so 
loud  as  a  small  cannon,  and  a  severe  shock  was  felt  at  our  feet,  just 
as  if  our  barge  had  struck  on  a  rock.  Almost  immediately,  a  very 
slight  swell  was  perceived  over  the  place  of  the  explosion,  and  the 
water  looked  rather  foamy :  then  in  about  a  second  it  began  to  rise, 
and  there  was  the  most  enormous  outbreak  of  spray  that  you  can 
conceive.  It  rose  in  one  column  of  60  or  70  feet  high,  and  broad 
at  the  base,  resembling  a  stumpy  sheaf  with  jagged  masses  of  spray 
spreading  out  at  the  sides,  and  seemed  to  grow  outwards  till  I  almost 
feared  that  it  was  coming  to  us.  It  sunk,  I  suppose,  in  separate 


AT   GREENWICH   OBSERVATORY.  147 

parts,  for  it  did  not  make  any  grand  squash  down,  and  then  there 
were  seen  logs  of  wood  rising,  and  a  dense  mass  of  black  mud,  which 
spread  gradually  round  till  it  occupied  a  very  large  space.  Fish 
were  stunned  by  it :  our  boatmen  picked  up  some.  It  was  said  by 
all  present  that  this  was  the  best  explosion  which  had  been  seen :  it 
was  truly  wonderful.  Then  we  sailed  to  Portsmouth The  explo- 
sion was  a  thing  worth  going  many  miles  to  see.  There  were  many 
yachts  and  sailing  boats  out  to  see  it  (I  counted  26  before  they  were 
at  the  fullest),  so  that  the  scene  was  very  gay. 


Here  are  some  notes  on  York  Cathedral  after  the  fire  : 

RED  LION  HOTEL,  REDCAR, 
1840,  Sept.  7. 

My  first  letter  was  closed  after  service  at  York  Cathedral.  As 
soon  as  I  had  posted  it,  I  walked  sedately  twice  round  the  cathedral, 
and  then  I  found  the  sexton  at  the  door,  who  commiserating  me  of 
my  former  vain  applications,  and  having  the  hope  of  lucre  before  his 
eyes,  let  me  in.  I  saw  the  burnt  part,  which  looks  not  melancholy 
but  unfinished.  Every  bit  of  wood  is  carried  away  clean,  with 
scarcely  a  smoke-daub  to  mark  where  it  has  been  :  the  building 
looks  as  if  the  walls  were  just  prepared  for  a  roof,  but  there  are 
some  deep  dints  in  the  pavement,  shewing  where  large  masses  have 
fallen.  The  lower  parts  of  some  of  the  columns  (to  the  height  of 
8  or  10  feet)  are  much  scaled  and  cracked.  The  windows  are 
scarcely  touched.  I  also  refreshed  my  memory  of  the  chapter-house, 
which  is  most  beautiful,  and  which  has  much  of  its  old  gilding 
reasonably  bright,  and  some  of  its  old  paint  quite  conspicuous.  And 
I  looked  again  at  the  old  crypt  with  its  late  Norman  work,  and  at 
the  still  older  crypt  of  the  pre-existing  church. 


1841 

"  The  routine  work  of  the  Observatory  in  its  several 
departments  was  carried  on  steadily  during  this  year.— The 
Camera  Obscura  was  removed  from  the  N.W.  Turret  of  the 
Great  Room,  to  make  way  for  the  Anemometer. — In  Mag- 

10 — 2 


148  GEORGE   BIDDELL  AIRY. 

netism  and  Meteorology  the  most  important  thing  was  the 
great  magnetic  storm  of  Sept.  25th,  which  revealed  a  new 
class  of  magnetic  phenomena.  It  was  very  well  observed  by 
Mr  Glaisher,  and  I  immediately  printed  and  circulated  an 
account  of  it. — In  April  I  reported  that  the  Planetary  Reduc- 
tions were  completed,  and  furnished  estimates  for  the  print- 
ing.— In  August  I  applied  for  18,000  copies  of  the  great 
skeleton  form  for  computing  Lunar  Tabular  Places,  which 
were  granted. — I  reported,  as  usual,  on  various  Papers  for 
the  Royal  Society,  and  was  still  engaged  on  the  Cavendish 
Experiment. — In  the  University  of  London  I  attended  the 
meeting  of  Dec.  8th,  on  the  reduction  of  Examiners'  salaries, 
which  were  extravagant. — I  furnished  Col.  Colby  with  a  plan 
of  a  new  Sector,  still  used  in  the  British  Survey. — I  appealed 
to  Colby  about  the  injury  to  the  cistern  on  the  Great  Gable 
in  Cumberland,  by  the  pile  raised  for  the  Survey  Signal. — 
On  Jan.  3rd  occurred  a  most  remarkable  tidal  disturbance : 
the  tide  in  the  Thames  was  5  feet  too  low.  I  endeavoured 
to  trace  it  on  the  coasts,  and  had  a  vast  amount  of  corre- 
spondence: but  it  elicited  little. 

"  Of  private  history :  I  was  a  short  time  in  Suffolk  in 
March. — On  Mar.  3 1st  I  started  with  my  wife  (whose  health 
had  suffered  much)  for  a  trip  to  Bath,  Bristol,  Cardiff,  Swan- 
sea, &c.  While  at  Swansea  we  received  news  on  Apr.  24th 
of  the  deadly  illness  of  my  dear  mother.  We  travelled  by 
Neath  and  Cardiff  to  Bath,  where  I  solicited  a  rest  for  my 
wife  from  my  kind  friend  Miss  Sutcliffe,  and  returned  alone 
to  Greenwich.  My  dear  mother  had  died  on  the  morning  of 
the  24th.  The  funeral  took  place  at  Little  Whelnetham 
(near  Bury)  on  May  1st,  where  my  mother  was  buried  by  the 
side  of  my  father.  We  went  to  Cambridge,  where  my  wife 
consulted  Dr  Haviland  to  her  great  advantage,  and  returned 
to  Greenwich  on  May  7th. — On  May  I4th  to  i6th  I  was  at 
Sanderstead  (Rev.  J.  Courtney)  with  Whewell  as  one  sponsor, 
at  the  christening  of  my  daughter  Hilda. — In  September  I 
went  for  a  trip  with  my  sister  to  Yorkshire  and  Cumberland, 


AT   GREENWICH   OBSERVATORY.  149 

in  the  course  of  which  we  visited  Dent  (Sedgwick's  birth- 
place), and  paid  visits  to  Mr  Wordsworth,  Miss  Southey,  and 
Miss  Bristow,  returning  to  Greenwich  on  the  3Oth  Sept. — 
From  June  I5th  to  iQth  I  visited  my  brother  at  Keysoe." 

The  following  extracts  are  from  letters  written  to  his  wife 
while  on  the  above  trip  in  Yorkshire  and  Cumberland : 

RED  LION  INN,  REDCAR, 
1841,  Sept.  ii. 

We  stopped  at  York :  went  to  the  Tavern  Hotel.  In  the  morn- 
ing (Friday)  went  into  the  Cathedral.  I  think  that  it  improves  on 
acquaintance.  The  nave  is  now  almost  filled  with  scaffolding  for 
the  repair  of  the  roof,  so  that  it  has  not  the  bare  unfinished  appear- 
ance that  it  had  when  I  was  there  last  year.  The  tower  in  which 
the  fire  began  seems  to  be  a  good  deal  repaired :  there  are  new  mul- 
lions  in  its  windows,  &c.  We  stopped  to  hear  part  of  the  service, 
which  was  not  very  effective. 


Here  are  notes  of  his  visit  to  Dentdale  in  Yorkshire,  the 
birthplace  of  his  friend  Sedgwick  : 

KING'S  HEAD,  KENDAL, 
1841,  Sept.  15. 

The  day  was  quite  fine,  and  the  hills  quite  clear.  The  ascent 
out  of  Hawes  is  dull ;  the  little  branch  dale  is  simple  and  monoto- 
nous, and  so  are  the  hills  about  the  great  dale  which  are  in  sight. 
The  only  thing  which  interested  us  was  the  sort  of  bird's-eye  view  of 
Hardraw  dell,  which  appeared  a  most  petty  and  insignificant  opening 
in  the  great  hill  side.  But  when  we  got  to  the  top  of  the  pass  there 
was  a  magnificent  view  of  Ingleborough.  The  dale  which  was  most 
nearly  in  front  of  us  is  that  which  goes  down  to  Ingleton,  past  the 
side  of  Ingleborough.  The  mountain  was  about  nine  miles  distant. 
We  turned  to  the  right  and  immediately  descended  Dent-dale.  The 
three  dales  (to  Hawes,  to  Ingleton,  and  to  Dent)  lay  their  heads 
together  in  a  most  amicable  way,  so  that,  when  at  the  top,  it  is 
equally  easy  to  descend  down  either  of  them.  We  found  very  soon 
that  Dent-dale  is  much  more  beautiful  than  that  by  which  we  had 
ascended.  The  sides  of  the  hills  are  steeper,  and  perhaps  higher : 
the  bottom  is  richer.  The  road  is  also  better.  The  river  is  a  con- 


150  GEORGE   BIDDELL  AIRY. 

tinued  succession  of  very  pretty  falls,  almost  all  of  which  have 
scooped  out  the  lower  strata  of  the  rock,  so  that  the  water  shoots 
clear  over.  For  several  miles  (perhaps  10)  it  runs  upon  bare  lime- 
stone without  a  particle  of  earth.  From  the  head  of  the  dale  to  the 
village  of  Dent  is  eight  miles.  At  ;about  half-way  is  a  new  chapel, 
very  neat,  with  a  transept  at  its  west  end.  The  village  of  Dent  is 
one  of  the  strangest  places  that  I  ever  saw.  Narrow  street,  up  and 
down,  with  no  possibility  of  two  carriages  bigger'-  than  children's 
carts  passing  each  other.  We  stopped,  at  the  head  inn  and  enquired 
about  the  Geolog:  but  he  is  not  in  the  country.  We  then  called 
on  his  brother,  who  was  much  surprised  and  pleased  to  see  us.  His 
wife  came  in  soon  after  (his  daughter  having  gone  with  a  party  to  see 
some  waterfall)  and  they  urged  us  to  stop  and  dine  with  them.  So 
we  walked  about  and  saw  every  place  about  the  house,  church,  and 
school,  connected  with  the  history  of  the  Geolog:  and  then  dined. 
I  promised  that  you  should  call  there  some  time  when  we  are  in  the 
north  together  and  spend  a  day  or  two  with  them.  Mr  Sedgwick 
says  it  is  reported  that  Whewell  will  take  Sedbergh  living  (which  is 
now  vacant :  Trinity  College  is  patron).  Then  we  had  our  chaise 
and  went  to  Sedbergh.  The  very  mouth  of  Dent-dale  is  more  con- 
tracted than  its  higher  parts.  Sedbergh  is  embosomed  among  lump- 
ing hills.  Then  we  had  another  carriage  to  drive  to  Kendal. 


Here  is  a  recollection  of  Wordsworth  : 

SALUTATION,  AMBLESIDE, 
1841,  Sept.  19. 

We  then  got  our  dinner  at  Lowwood,  and  walked  straight  to 
Ambleside,  changed  our  shoes,  and  walked  on  to  Rydal  to  catch 
Wordsworth  at  tea.  Miss  Wordsworth  was  being  drawn  about  in  a 
chair  just  as  she  was  seven  years  ago.  I  do  not  recollect  her  appear- 
ance then  so  as  to  say  whether  she  is  much  altered,  but  I  think  not. 
Mr  Wordsworth  is  as  full  of  good  talk  as  ever,  and  seems  quite 
strong  and  well.  Mrs  Wordsworth  looks  older.  Their  son  William 
was  at  tea,  but  he  had  come  over  only  for  the  day  or  evening. 
There  was  also  a  little  girl,  who  I  think  is  Mrs  Wordsworth's  niece. 


AT  GREENWICH   OBSERVATORY.  151 


1842 

"  In  this  year  I  commenced  a  troublesome  work,  the 
Description  of  the  Northumberland  Telescope.  On  Sept. 
9th  I  wrote  to  the  Duke  of  Northumberland  suggesting  this, 
sending  him  a  list  of  Plates,  and  submitting  an  estimate  of 
expense  £120.  On  Sept.  iQth  I  received  the  Duke's  assent. 
I  applied  to  Prof.  Challis  (at  the  Cambridge  Observatory) 
requesting  him  to  receive  the  draughtsman,  Sly,  in  his  house, 
which  he  kindly  consented  to  do. 

"  With  regard  to  Estimates.  I  now  began  to  point  out  to 
the  Admiralty  the  inconvenience  of  furnishing  separate  esti- 
mates, viz.  to  the  Admiralty  for  the  Astronomical  Establish- 
ment, and  to  the  Treasury  for  the  Magnetical  and  Meteoro- 
logical Establishment. — The  great  work  of  the  Lunar 
Reductions  proceeded  steadily  :  14  computers  were  employed 
on  them. — With  regard  to  the  Magnetical  and  Meteorological 
Establishment :  I  suppose  that  James  Ross's  expedition  had 
returned  :  and  with  this,  according  to  the  terms  of  the  original 
grant,  the  Magnetical  and  Meteorological  Establishments 
expired.  There  was  much  correspondence  with  the  Royal 
Society  and  the  Treasury,  and  ultimately  Sir  R.  Peel  con- 
sented to  the  continuation  of  the  establishments  to  the  end 
of  1845. — In  this  year  began  my  correspondence  with  Mr 
Mitchell  about  the  Cincinnati  Observatory.  On  Aug.  25  Mr 
Mitchell  settled  himself  at  Greenwich,  and  worked  for  a  long 
time  in  the  Computing  Room. — And  in  this  year  Mr  Aiken  of 
Liverpool  first  wrote  to  me  about  the  Liverpool  Observatory, 
and  a  great  deal  of  correspondence  followed :  the  plans  were 
in  fact  entirely  entrusted  to  me. — July  7th  was  the  day  of  the 
Total  Eclipse  of  the  Sun,  which  I  observed  with  my  wife  at 
the  Superga,  near  Turin.  I  wrote  an  account  of  my  observa- 
tions for  the  Royal  Astronomical  Society. — On  Jan.  loth  I 
notified  to  Mr  Goulburn  that  our  Report  on  the  Restoration 
of  the  Standards  was  ready,  and  on  Jan.  I2th  I  presented  it. 


152  GEORGE   BIDDELL  AIRY. 

After  this  followed  a  great  deal  of  correspondence,  principally 
concerning  the  collection  of  authenticated  copies  of  the  Old 
Standards  from  all  sides. — In  some  discussions  with  Capt. 
Shirreff,  then  Captain  Superintendent  of  the  Chatham  Dock- 
yard, I  suggested  that  machinery  might  be  made  which 
would  saw  ship-timbers  to  their  proper  form,  and  I  sent  him 
some  plans  on  Nov.  8th.  This  was  the  beginning  of  a  corre- 
spondence which  lasted  long,  but  which  led  to  nothing,  as 
will  appear  hereafter. — On  Dec.  I5th,  being  on  a  visit  to 
Dean  Peacock  at  Ely,  I  examined  the  Drainage  Scoop  Wheel 
at  Prickwillow,  and  made  a  Report  to  him  by  letter,  which 
obtained  circulation  and  was  well  known. — On  May  26th  the 
manuscript  of  my  article,  '  Tides  and  Waves,'  for  the  Ency- 
clopaedia Metropolitana  was  sent  to  the  printer.  I  had  exten- 
sive correspondence,  principally  on  local  tides,  with  Whewell 
and  others.  Tides  were  observed  for  me  by  Colby's  officers 
at  Southampton,  by  myself  at  Christchurch  and  Poole,  at 
Ipswich  by  Ransome's  man ;  and  a  great  series  of  observa- 
tions of  Irish  Tides  were  made  on  my  plan  under  Colby's 
direction  in  June,  July  and  August. — On  Sept.  I5th  Mr 
Goulburn,  Chancellor  of  the  Exchequer,  asked  my  opinion  on 
the  utility  of  Babbage's  calculating  machine,  and  the  pro- 
priety of  expending  further  sums  of  money  on  it.  I  replied, 
entering  fully  into  the  matter,  and  giving  my  opinion  that  it 
was  worthless. — I  was  elected  an  Honorary  Member  of  the 
Institution  of  Civil  Engineers,  London. 

"  The  reduction  and  printing  of  the  astronomical  observa- 
tions had  been  getting  into  arrear  :  the  last  revise  of  the  1840 
observations  went  to  press  on  May  i8th,  1842.  On  Aug. 
1 8th  came  into  operation  a  new  organization  of  Assistants' 
hours  of  attendance,  &c.,  required  for  bringing  up  reductions. 
I  worked  hard  myself  and  my  example  had  good  effect."  His 
reference  to  this  subject  in  his  Report  to  the  Visitors  is  as 
follows  :  "  I  have  in  one  of  the  preceding  articles  alluded  to 
the  backwardness  of  our  reductions.  In  those  which  follow 
it  I  trust  that  I  have  sufficiently  explained  it.  To  say  nothing 


AT  GREENWICH   OBSERVATORY.  153 

of  the  loss,  from  ill  health,  of  the  services  of  most  efficient 
assistants,  I  am  certain  that  the  quantity  of  current  work  will 
amply  explain  any  backwardness.  Perhaps  I  may  particu- 
larly mention  that  in  the  observations  of  1840  there  was  an 
unusual  quantity  of  equatoreal  observations,  and  the  reduc- 
tions attending  these  occupied  a  very  great  time.  But,  as 
regards  myself,  there  has  been  another  cause.  The  reduction 
of  the  Ancient  Lunar  and  Planetary  Observations,  the  atten- 
tion to  chronometer  constructions,  the  proposed  management 
of  the  printing  of  papers  relating  to  important  operations  at 
the  Cape  of  Good  Hope  ;  these  and  similar  operations  have 
taken  up  much  of  my  time.  I  trust  that  I  am  doing  well  in 
rendering  Greenwich,  even  more  distinctly  than  it  has  been 
heretofore,  the  place  of  reference  to  all  the  world  for  the 
important  observations,  and  results  of  observations,  on  which 
the  system  of  the  universe  is  founded.  As  regards  myself,  I 
have  been  accustomed,  in  these  matters,  to  lay  aside  private 
considerations ;  to  consider  that  I  am  not  a  mere  Superin- 
tendent of  current  observations,  but  a  Trustee  for  the  honour 
of  Greenwich  Observatory  generally,  and  for  its  utility  gene- 
rally to  the  world ;  nay,  to  consider  myself  not  as  mere 
Director  of  Greenwich  Observatory,  but  (however  unworthy 
personally)  as  British  Astronomer,  required  sometimes  by  my 
office  to  interfere  (when  no  personal  offence  is  given)  in  the 
concerns  of  other  establishments  of  the  State.  If  the  Board 
supports  me  in  this  view  there  can  be  little  doubt  that  the 
present  delay  of  computations,  relating  to  current  observa- 
tions, will  be  considered  by  them  as  a  very  small  sacrifice  to 
the  important  advantage  that  may  be  gained  by  proper  atten- 
tion to  the  observations  of  other  times  and  other  places." 

"  Of  private  history :  In  February  I  went  for  a  week  to 
Playford  and  Norwich,  visiting  Prof.  Sedgwick  at  the  latter 
place.  On  Mar.  ist  my  third  daughter  Christabel  was  born. 
In  March  I  paid  a  short  visit  to  Sir  John  Herschel  at  Hawk- 
hurst.  From  June  I2th  to  Aug.  nth  I  was  travelling  with 
my  wife  on  the  Continent,  being  partly  occupied  with  the 


154  GEORGE   BIDDELL  AIRY. 

observation  of  the  Total  Eclipse  of  the  Sun  on  July  7th. 
The  journey  was  in  Switzerland  and  North  Italy.  In  Decem- 
ber I  went  to  Cambridge  and  Ely,  visiting  Dr  Peacock  at  the 
latter  place."  £. 

From  Feb.  23rd  to  28th  Airy  was  engaged  on  Observa- 
tions of  Tides  at  Southampton,  Christchurch,  Poole,  and 
Weymouth.  During  this  expedition  he  wrote  frequently  (as 
he  always  did)  to  his  wife  on  the  incidents  of  his  journey, 
and  the  following  letters  appear  characteristic  : 

KING'S  ARMS,  CHRISTCHURCH, 
OR  XCHURCH, 

1842,  Feb.  24. 

The  lower  of  the  above  descriptions  of  my  present  place  of 
abode  is  the  correct  one,  as  I  fearlessly  assert  on  the  authority  of 
divers  direction-posts  on  the  roads  leading  to  it  (by  the  bye  this 
supports  my  doctrine  that  x  in  Latin  was  not  pronounced  eks  but 
khi,  because  the  latter  is  the  first  letter  of  Christ,  for  which  x  is  here 
traditionally  put).  Finding  this  morning  that  Yolland  (who  called 
on  me  as  soon  as  I  had  closed  the  letter  to  you)  was  perfectly 
inclined  to  go  on  with  the  tide  observations  at  Southampton,  and 
that  his  corporals  of  sappers  were  conducting  them  in  the  most 
exemplary  manner,  I  determined  on  starting  at  once.  However  we 
first  went  to  look  at  the  New  Docks  (mud  up  to  the  knees)  and  truly 
it  is  a  very  great  work.  There  is  to  be  enclosed  a  good  number  of 
acres  of  water  22  feet  deep:  one  dock  locked  in,  the  other  a  tidal 
dock  or  basin  with  that  depth  at  low  water.  They  are  surrounded 
by  brick  walls  eight  feet  thick  at  top,  10  or  more  at  bottom ;  and  all 
the  parts  that  ever  can  be  exposed  are  faced  with  granite.  The 
people  reckon  that  this  work  when  finished  will  attract  a  good  deal 
of  the  London  commerce,  and  I  should  not  be  surprised  at  it.  For 
it  is  very  much  easier  for  ships  to  get  into  Southampton  than  into 
London,  and  the  railway  carriage  will  make  them  almost  one.  A 
very  large  steamer  is  lying  in  Southampton  Water :  the  Oriental, 
which  goes  to  Alexandria.  The  Lady  Mary  Wood,  a  large  steamer 
for  Lisbon  and  Gibraltar,  was  lying  at  the  pier.  The  said  pier  is  a 
very  pleasant  place  of  promenade,  the  water  and  banks  are  so  pretty, 
and  there  is  so  much  liveliness  of  ships  about  it.  Well  I  started  in 
a  gig,  in  a  swashing  rain,  which  continued  off  and  on  for  a  good 
while.  Of  the  21  miles,  I  should  think  that  15  were  across  the  New 


AT  GREENWICH   OBSERVATORY.  155 

Forest.  I  do  not  much  admire  it.  As  for  Norman  William's  destruc- 
tion of  houses  and  churches  to  make  it  hunting  ground,  that  is  utter 
nonsense  which  never  could  have  been  written  by  anybody  that  ever 
saw  it:  but  as  to  hunting,  except  his  horses  wore  something  like 
mud-pattens  or  snow-shoes,  it  is  difficult  to  conceive  it.  Almost 
the  whole  Forest  is  like  a  great  sponge,  water  standing  in  every  part. 
In  the  part  nearer  to  Xchurch  forest  trees,  especially  beeches,  seem 
to  grow  well.  We  stopped  to  bait  at  Lyndhurst,  a  small  place  high 
up  in  the  Forest :  a  good  view,  such  as  it  is,  from  the  churchyard. 
The  hills  of  the  Isle  of  Wight  occasionally  in  sight.  On  approaching 
Xchurch  the  chalk  cliffs  of  the  west  end  of  the  Isle  of  Wight  (leading 
to  the  Needles)  were  partly  visible ;  and,  as  the  sun  was  shining  on 
them,  they  fairly  blazed.  Xchurch  is  a  small  place  with  a  magnifi- 
cent-looking church  (with  lofty  clerestory,  double  transept,  &c.,  but 
with  much  irregularity)  which  I  propose  to  visit  to-morrow.  Also  a 
ruin  which  looks  like  an  abbey,  but  the  people  call  it  a  castle.  There 
is  a  good  deal  of  low  land  about  it,  and  the  part  between  the  town 
and  the  sea  reminded  me  a  good  deal  of  the  estuary  above  Cardigan, 
flat  ill-looking  bogs  (generally  islands)  among  the  water.  I  walked 
to  the  mouth  of  the  river  (more  than  two  miles)  passing  a  nice  little 
place  called  Sandford,  with  a  hotel  and  a  lot  of  lodgings  for  summer 
sea-people.  At  the  entrance  of  the  river  is  a  coastguard  station,  and 
this  I  find  is  the  place  to  which  I  must  go  in  the  morning  to  observe 
the  tide.  I  had  some  talk  with  the  coastguard  people,  and  they 
assure  me  that  the  tide  is  really  double  as  reported.  As  I  came 
away  the  great  full  moon  was  rising,  and  I  could  read  in  her  unusu- 
ally broad  face  (indicating  her  nearness  to  the  earth)  that  there  will 
be  a  powerful  tide.  I  came  in  and  have  had  dinner  and  tea,  and  am 
now  going  to  bed,  endeavouring  to  negociate  for  a  breakfast  at  six 
o'clock  to-morrow  morning.  It  is  raining  cats  and  dogs. 


LUCE'S  HOTEL,  WEYMOUTH, 
1842,  Feb.  27. 

This  morning  when  I  got  up  I  found  that  it  was  blowing  fresh 
from  S.W.  and  the  sea  was  bursting  over  the  wall  of  the  eastern 
extremity  of  the  Esplanade  very  magnanimously.  So  (the  swell  not 
being  favourable  for  tide-observations)  I  gave  them  up  and  deter- 
mined to  go  to  see  the  surf  on  the  Chesil  Bank.  I  started  with  my 
great-coat  on,  more  for  defence  against  the  wind  than  against  rain ; 


156  GEORGE   BIDDELL  AIRY. 

but  in  a  short  time  it  began  to  rain,  and  just  when  I  was  approaching 
the  bridge  which  connects  the  mainland  with  the  point  where  the 
Chesil  Bank  ends  at  Portland  (there  being  an  arm  of  the  sea  behind 
the  Chesil  Bank)  it  rained. and  blew  most  dreadfully.  However  I 
kept  on  and  mounted  the  bank  and  ^descended  a  little  way  towards 
the  sea,  and  there  was  the  surf  in  all  its  glory.  I  cannot  give  you 
an  idea  of  its  majestic  appearance.  It  was  evidently  very  high,  but 
that  was  not  the  most  striking  part  of  it,  for  there  was  no  such  thing 
as  going  within  a  considerable  distance  of  it  (the  occasional  outbreaks 
of  the  water  advancing  so  far)  so  that  its  magnitude  could  not  be 
well  seen.  My  impression  is  that  the  height  of  the  surf  was  from  10 
to  20  feet.  But  the  striking  part  was  the  clouds  of  solid  spray  which 
formed  immediately  and  which  completely  concealed  all  the  other 
operations  of  the  water.  They  rose  a  good  deal  higher  than  the  top 
of  the  surf,  so  the  state  of  things  was  this.  A  great  swell  is  seen 
coming,  growing  steeper  and  steeper ;  then  it  all  turns  over  and  you 
see  a  face  just  like  the  pictures  of  falls  of  Niagara;  but  in  a  little 
more  than  one  second  this  is  totally  lost  and  there  is  nothing  before 
you  but  an  enormous  impenetrable  cloud  of  white  spray.  In  about 
another  second  there  comes  from  the  bottom  of  this  cloud  the  foam- 
ing current  of  water  up  the  bank,  and  it  returns  grating  the  pebbles 
together  till  their  jar  penetrates  the  very  brain.  I  stood  in  the  face 
of  the  wind  and  rain  watching  this  a  good  while,  and  should  have 
stood  longer  but  that  I  was  so  miserably  wet.  It  appeared  to  me 
that  the  surf  was  higher  farther  along  the  bank,  but  the  air  was  so 
thickened  by  the  rain  and  the  spray  that  I  could  not  tell.  When  I 
returned  the  bad  weather  abated.  I  have  now  borrowed  somebody 
else's  trowsers  while  mine  are  drying  (having  got  little  wet  in  other 
parts,  thanks  to  my  great-coat,  which  successfully  brought  home  a 
hundredweight  of  water),  and  do  not  intend  to  stir  out  again  except 
perhaps  to  post  this  letter. 


FLAMST-EED  HOUSE, 

1842,  May  15. 

Yesterday  after  posting  the  letter  for  you  I  went  per  steamboat 
to  Hungerford.  I  then  found  Mr  Vignoles,  and  we  trundled  off 
together,  with  another  engineer  named  Smith,  picking  up  Stratford 
by  the  way,  to  Wormwood  Scrubs.  There  was  a  party  to  see  the 
Atmospheric  Railway  in  action  :  including  (among  others)  Sir  John 


AT  GREENWICH   OBSERVATORY.  157 

Burgoyne,  whom  I  met  in  Ireland  several  years  ago,  and  Mr  Pym, 
the  Engineer  of  the  Dublin  and  Kingstown  Railway,  whom  I  have 
seen  several  times,  and  who  is  very  sanguine  about  this  construction  ; 
and  Mr  Clegg,  the  proposer  of  the  scheme  (the  man  that  invented 
gas  in  its  present  arrangements),  and  Messrs  Samuda,  two  Jews  who 
are  the  owners  of  the  experiment  now  going  on ;  and  Sir  James 
South  !  With  the  latter  hero  and  mechanician  we  did  not  come  in 
contact.  Unfortunately  the  stationary  engine  (for  working  the  air- 
pump  which  draws  the  air  out  of  the  pipes  and  thus  sucks  the 
carriages  along)  broke  down  during  the  experiment,  but  not  till  we 
had  seen  the  carriage  have  one  right  good  run.  And  to  be  sure  it  is 
very  funny  to  see  a  carriage  running  all  alone  "  as  if  the  Devil  drove 
it "  without  any  visible  cause  whatever.  The  mechanical  arrange- 
ments we  were  able  to  examine  as  well  after  the  engine  had  broken 
down  as  at  any  time.  And  they  are  very  simple  and  apparently 
very  satisfactory,  and  there  is  no  doubt  of  the  mechanical  practica- 
bility of  the  thing  even  in  places  where  locomotives  can  hardly  be 
used :  whether  it  will  pay  or  not  is  doubtful.  I  dare  say  that  the 
Commissioners'  Report  has  taken  a  very  good  line  of  discrimination . 


1843 

"  In  March  I  wrote  to  Dr  Wynter  (Vice-Chancellor)  at 
Oxford,  requesting  permission  to  see  Bradley's  and  Bliss's 
manuscript  Observations,  with  the  view  of  taking  a  copy  of 
them.  This  was  granted,  and  the  books  of  Transits  were 
subsequently  copied  under  Mr  Breen's  superintendence. — 
The  following  paragraph  is  extracted  from  the  Report  to  the 
Visitors :  '  In  the  Report  of  last  year,  I  stated  that  our  reduc- 
tions had  dropped  considerably  in  arrear.  I  have  the  satis- 
faction now  of  stating  that  this  arrear  and  very  much  more 
have  been  completely  recovered,  and  that  the  reductions  are 
now  in  as  forward  a  state  as  at  any  time  since  my  connection 
with  the  Observatory.'  In  fact  the  observations  of  1842  were 
sent  to  press  on  Mar.  1st,  1843. — About  this  year  the  Annual 
Dinner  at  the  Visitation  began  to  be  more  important,  princi- 
pally under  the  management  of  Capt.  W.  H.  Smyth,  R.N. — 
In  November  I  was  enquiring  about  an  8-inch  object-glass. 


158  GEORGE   BIDDELL  AIRY. 

I  had  already  in  mind  the  furnishing  of  our  meridional  instru- 
ments with  greater  optical  powers. — On  July  I4th  the  Admi- 
ralty referred  to  me  a  Memorial  of  Mr  J.  G.  Ulrich,  a  chrono- 
meter maker,  claiming  a  reward  ftfr  improvements  in  chrono- 
meters. I  took  a  great  deal  of  trouble  in  the  investigation  of 
this  matter,  by  books,  witnesses,  Sec.,  and  finally  reported  on 
Nov.  4th  that  there  was  no  ground  for  claim. —  In  April  I 
received  the  first  application  of  the  Royal  Exchange  Com- 
mittee, for  assistance  in  the  construction  of  the  Clock  :  this 
led  to  a  great  deal  of  correspondence,  especially  with  Dent. — 
The  Lunar  Reductions  were  going  on  in  full  vigour. — I  had 
much  work  in  connection  with  the  Cape  Observatory :  partly 
about  an  equatoreal  required  for  the  Observatory,  but  chiefly 
in  getting  Maclear's  work  through  the  press. — In  this  year  I 
began  to  think  seriously  of  determining  the  longitude  of 
Valencia  in  Ireland,  as  a  most  important  basis  for  the  scale 
of  longitude  in  these  latitudes,  by  the  transmission  of  chrono- 
meters ;  and  in  August  I  went  to  Valencia  and  examined  the 
localities.  In  September  I  submitted  a  plan  to  the  Admi- 
ralty, but  it  was  deferred. — The  new  Commission  for  restoring 
the  Standards  was  appointed  on  June  2Oth,  I  being  Chair- 
man. The  work  of  collecting  standards  and  arranging  plans 
was  going  on ;  Mr  Baily  attending  to  Standards  of  Length, 
and  Prof.  W.  H.  Miller  to  Standards  of  Weight.  We  held 
two  meetings. — A  small  assistance  was  rendered  to  me  by 
Mr  Charles  May  (of  the  firm  of  Ransomes  and  May),  which 
has  contributed  much  to  the  good  order  of  papers  in  the 
Observatory.  Mr  Robert  Ransome  had  remarked  my  method 
of  punching  holes  in  the  paper  by  a  hand-punch,  the  places 
of  the  holes  being  guided  by  holes  in  a  piece  of  card,  and 
said  that  they  could  furnish  me  with  something  better.  Ac- 
cordingly, on  Aug.  28th  Mr  May  sent  me  the  punching 
machine,  the  prototype  of  all  now  used  in  the  Observatory. 

"  On  Sept.  25th  was  made  my  proposal  for  an  Altazimuth 
Instrument  for  making  observations  of  the  Moon's  place 
more  frequently  and  through  parts  of  her  orbit  where  she 


AT   GREENWICH   OBSERVATORY,  159 

could  never  be  observed  with  meridional  instruments ;  the 
most  important  addition  to  the  Observatory  since  its  founda- 
tion. The  Board  of  Visitors  recommended  it  to  the  Admi- 
ralty, and  the  Admiralty  sanctioned  the  construction  of  the 
instrument  and  the  building  to  contain  it."  The  following 
passage  is  quoted  from  the  Address  of  the  Astronomer  Royal 
to  the  Board  of  Visitors  at  the  Special  Meeting  of  Nov.  loth, 
1843:  "The  most  important  object  in  the  institution  and 
maintenance  of  the  Royal  Observatory  has  always  been  the 
Observations  of  the  Moon.  In  this  term  I  include  the  deter- 
mination of  the  places  of  fixed  stars  which  are  necessary  for 
ascertaining  the  instrumental  errors  applicable  to  the  instru- 
mental observations  of  the  Moon.  These,  as  regards  the 
objects  of  the  institution,  were  merely  auxiliaries  :  the  history 
of  the  circumstances  which  led  the  Government  of  the  day  to 
supply  the  funds  for  the  construction  of  the  Observatory 
shews  that,  but  for  the  demands  of  accurate  Lunar  Determi- 
nations as  aids  to  navigation,  the  erection  of  a  National 
Observatory  would  never  have  been  thought  of.  And  this 
object  has  been  steadily  kept  in  view  when  others  (necessary 
as  fundamental  auxiliaries)  were  passed  by.  Thus,  during 
the  latter  part  of  Bradley 's  time,  and  Bliss's  time  (which  two 
periods  are  the  least  efficient  in  the  modern  history  of  the 
Observatory),  and  during  the  latter  part  of  Maskelyne's 
presidency  (when,  for  years  together,  there  is  scarcely  a 
single  observation  of  the  declination  of  a  star),  the  Observa- 
tions of  the  Moon  were  kept  up  with  the  utmost  regularity. 
And  the  effect  of  this  regularity,  as  regards  its  peculiar  object, 
has  been  most  honourable  to  the  institution.  The  existing 
Theories  and  Tables  of  the  Moon  are  founded  entirely  upon 
the  Greenwich  Observations ;  the  Observatory  of  Greenwich 
has  been  looked  to  as  that  from  which  alone  adequate  obser- 
vations can  be  expected,  and  from  which  they  will  not  be 
expected  in  vain :  and  it  is  not  perhaps  venturing  too  much 
to  predict  that,  unless  some  gross  dereliction  of  duty  by  the 
managers  of  the  Observatory  should  occur,  the  Lunar  Tables 


l6o  GEORGE   BIDDELL  AIRY. 

will  always  be  founded  on  Greenwich  Observations.  With 
this  impression  it  has  long  been  to  me  a  matter  of  considera- 
tion whether  means  should  not  be  taken  for  rendering  the 
series  of  Observations  of  the  Mbon  more  complete  than  it 
can  be  made  by  the  means  at  present  recognized  in  our 
observatories." — In  illustration  of  the  foregoing  remarks,  the 
original  inscription  still  remaining  on  the  outside  of  the  wall 
of  the  Octagon  Room  of  the  Observatory  may  be  quoted. 
It  runs  thus:  '  Carolus  IIs  Rex  Optimus  Astronomiae  et 
Nauticae  Artis  Patronus  Maximus  Speculam  hanc  in  utri- 
usque  commodum  fecit  Anno  Dni  MDCLXXVI  Regni  sui 
XXVIII  curante  lona  Moore  milite  RTSG.' 

"  The  Ashburton  Treaty  had  been  settled  with  the  United 
States,  for  the  boundary  between  Canada  and  the  State  of 
Maine,  and  one  of  its  conditions  was,  that  a  straight  line 
about  65  miles  in  length  should  be  drawn  through  dense 
woods,  connecting  definite  points.  It  soon  appeared  that 
this  could  scarcely  be  done  except  by  astronomical  opera- 
tions. Lord  Canning,  Under  Secretary  of  the  Foreign  Office, 
requested  me  to  nominate  two  astronomers  to  undertake  the 
work.  I  strongly  recommended  that  Military  Officers  should 
carry  out  the  work,  and  Capt.  Robinson  and  Lieut.  Pipon 
were  detached  for  this  service.  On  Mar.  ist  they  took 
lodgings  at  Greenwich,  and  worked  at  the  Observatory  every 
day  and  night  through  the  month.  My  detailed  astronomical 
instructions  to  them  were  drawn  out  on  Mar.  29th.  I  pre- 
pared all  the  necessary  skeleton  forms,  &c.,  and  looked  to 
their  scientific  equipment  in  every  way.  The  result  will  be 
given  in  1844. 

"  Of  private  history :  In  January  I  went  to  Dover  with 
my  wife  to  see  the  blasting  of  a  cliff  there :  we  also  visited 
Sir  J.  Herschel  at  Hawkhurst.  In  April  I  was  at  Playford, 
on  a  visit  to  Arthur  Biddell.  On  Apr.  9th  my  daughter 
Annot  was  born.  From  July  22nd  to  August  25th  I  was 
travelling  in  the  South  of  Ireland,  chiefly  to  see  Valencia 
and  consider  the  question  of  determining  its  longitude: 


AT   GREENWICH   OBSERVATORY.  l6l 

during  this  journey  I  visited  Lord  Rosse  at  Birr  Castle,  and 
returned  to  Weymouth,  where  my  family  were  staying  at  the 
time.  In  October  I  visited  Cambridge,  and  in  December  I 
was  again  at  Playford." 

The  journey  to  Cambridge  (Oct.  24th  to  27th)  was  ap- 
parently in  order  to  be  present  on  the  occasion  of  the  Queen's 
visit  there  on  the  25th :  the  following  letter  relating  to  it 
was  written  to  his  wife: 

SEDGWICK'S  ROOMS, 
TRINITY  COLLEGE,  CAMBRIDGE. 

1843,  Oct.  26,  Thursday. 

I  have  this  morning  received  your  letter :  I  had  no  time  to  write 
yesterday.  There  are  more  things  to  tell  of  than  I  can  possibly 
remember.  The  Dean  of  Ely  yesterday  was  in  a  most  ludicrous 
state  of  misery  because  his  servant  had  sent  his  portmanteau  (con- 
taining his  scarlet  academicals  as  well  as  everything  else)  to  London, 
and  it  went  to  Watford  before  it  was  recovered  :  but  he  got  it  in  time 
to  shew  himself  to-day.  Yesterday  morning  I  came  early  to  break- 
fast with  Sedgwick.  Then  I  walked  about  the  streets  to  look  at  the 
flags.  Cambridge  never  had  such  an  appearance  before.  In  looking 
along  Trinity  Street  or  Trumpington  Street  there  were  arches  and 
flags  as  close  as  they  could  stand,  and  a  cord  stretched  from  King's 
Entrance  to  Mr  Deck's  or  the  next  house  with  flags  on  all  its  length  : 
a  flag  on  St  Mary's,  and  a  huge  royal  standard  ready  to  hoist  on 
Trinity  Gateway :  laurels  without  end.  I  applied  at  the  Registrar's 
office  for  a  ticket  which  was  to  admit  me  to  Trinity  Court,  the  Senate 
House,  &c.,  and  received  from  Peacock  one  for  King's  Chapel. 
Then  there  was  an  infinity  of  standing  about,  and  very  much  I  was 
fatigued,  till  I  got  some  luncheon  at  Blakesley's  rooms  at  i  o'clock. 
This  was  necessary  because  there  was  to  be  no  dinner  in  hall  on 
account  of  the  Address  presentation.  The  Queen  was  expected  at  2, 
and  arrived  about  10  minutes  after  2.  When  she  drove  up  to  Trinity 
Gate,  the  Vice-Chancellor,  masters,  and  beadles  went  to  meet  her, 
and  the  beadles  laid  down  their  staves,  which  she  desired  them  to 
take  again.  Then  she  came  towards  the  Lodge  as  far  as  the  Sun- 
dial, where  Whewell  as  master  took  the  college  keys  (a  bundle  of 
rusty  keys  tied  together  by  a  particularly  greasy  strap)  from  the 
bursar  Martin,  and  handed  them  to  the  Queen,  who  returned  them. 
Then  she  drove  round  by  the  turret-corner  of  the  court  to  the  Lodge 

A.  B,  II 


162  GEORGE  BIDDELL  AIRY. 


door.  Almost  every  member  of  the  University  was  in  the  court,  and 
there  was  a  great  hurraing  except  when  the  ceremonies  were  going 
forward.  Presently  the  Queen  appeared  at  a  window  and  bowed, 
and  was  loudly  cheered.  .Then  notice  was  given  that  the  Queen  and 
Prince  would  receive  the  Addresses  ;"pf  the  University  in  Trinity  hall, 
and  a  procession  was  formed,  in  which  I  had  a  good  place,  as  I 
claimed  rank  with  the  Professors.  A  throne  and  canopy  were 
erected  at  the  top  of  the  hall,  but  the  Queen  did  riot  sit,  which  was 
her  own  determination,  because  if  she  had  sat  it  would  have  been 
proper  that  everybody  should  back  out  before  presenting  the  Address 
to  the  Prince  :  which  operation  would  have  suffocated  at  least  100 
people.  The  Queen  wore  a  blue  gown  and  a  brown  shawl  with  an 
immense  quantity  of  gold  embroidery,  and  a  bonnet.  Then  it  was 
known  that  the  Queen  was  going  to  service  at  King's  Chapel  at  half 
past  three  :  so  everybody  went  there.  I  saw  the  Queen  walk  up  the 
antechapel  and  she  looked  at  nothing  but  the  roof.  I  was  not  able 
to  see  her  in  chapel  or  to  see  the  throne  erected  for  her  with  its  back 
to  the  Table,  which  has  given  great  offence  to  many  people.  (I 
should  have  said  that  before  the  Queen  came  I  called  on  Dr  Havi- 
land,  also  on  Scholefield,  also  on  the  Master  of  Christ's.)  After  this 
she  returned  to  Trinity,  and  took  into  her  head  to  look  at  the  chapel. 
The  cloth  laid  on  the  pavement  was  not  long  enough  and  the  under- 
graduates laid  down  their  gowns.  Several  of  the  undergraduate 
noblemen  carried  candles  to  illuminate  Newton's  statue.  After  this 
the  Prince  went  by  torchlight  to  the  library.  Then  I  suppose  came 
dinner,  and  then  it  was  made  known  that  at  half-past  nine  the  Queen 
would  receive  some  Members  of  the  University.  So  I  rigged  myself 
up  and  went  to  the  leve'e  at  the  Lodge  and  was  presented  in  my  turn 
by  the  Vice-Chancellor  as  "  Ex-Professor  Airy,  your  Majesty's  As- 
tronomer Royal."  The  Queen  and  the  Prince  stood  together,  and  a 
bow  was  made  to  and  received  from  each.  The  Prince  recognised 
me  and  said  "  I  am  glad  to  see  you,"  or  something  like  that.  Next 
to  him  stood  Goulburn,  and  next  Lord  Lyndhurst,  who  to  my  great 
surprise  spoke  very  civilly  to  me  (as  I  will  tell  you  afterwards).  The 
Queen  had  her  head  bare  and  a  sort  of  French  white  gown  and 
looked  very  well.  She  had  the  ribbon  of  the  Garter  on  her  breast ; 
but  like  a  ninny  I  forgot  to  look  whether  she  had  the  Garter  upon 
her  arm.  The  Prince  wore  his  Garter.  I  went  to  bed  dead  tired  and 
got  up  with  a  headache. — About  the  degree  to  the  Prince  and  the 
other  movements  I  will  write  again. 


AT  GREENWICH   OBSERVATORY.  163 

Here  is  a  note  from  Cubitt  relating  to  the  blasting  of  the 
Round  Down  Cliff  at  Dover  referred  to  above : 

GREAT  GEORGE  STREET, 

Jan.  2oth,  1843. 
MY  DEAR  SIR, 

Thursday  next  the  26th  at  12  is  the  time  fixed  for  the 
attempt  to  blow  out  the  foot  of  the  "  Round  Down  "  Cliff  near 
Dover. 

The  Galvanic  apparatus  has  been  repeatedly  tried  in  place — that 
is  by  exploding  cartridges  in  the  very  chambers  of  the  rock  prepared 
for  the  powder — with  the  batteries  at  1200  feet  distance  they  are  in 
full  form  and  act  admirably  so  that  I  see  but  little  fear  of  failure  on 
that  head. 

They  have  been  rehearsing  the  explosions  on  the  plan  I  most 
strongly  recommended,  that  is — to  fire  each  chamber  by  an  indepen- 
dent battery  and  circuit  and  to  discharge  the  three  batteries  simul- 
taneously by  signal  or  word  of  command  which  answers  well  and  "  no 
mistake." 

I  shall  write  to  Sir  John  Herschel  to-day,  and  remain 

My  dear  Sir, 

Very  truly  yours, 

W.  CUBITT. 
G.  B.  Airy,  Esq. 


The  following  extracts  are  from  letters  to  his  wife 
written  in  Ireland  when  on  his  journey  to  consider  the 
determination  of  the  longitude  of  Valencia. 

SKIBBEREEN, 

1843,  July  28. 

By  the  bye,  to  shew  the  quiet  of  Ireland  now,  I  saw  in  a  news- 
paper at  Cork  this  account.  At  some  place  through  which  a  repeal- 
association  was  to  pass  (I  forget  its  name)  the  repealers  of  the  place 
set  up  a  triumphal  arch.  The  police  pulled  it  down,  and  were  pelted 
by  the  repealers,  and  one  of  the  policemen  was  much  bruised. 
O'Connell  has  denounced  this  place  as  a  disgrace  to  the  cause  of 
repeal,  and  has  moved  in  the  full  meeting  that  the  inhabitants  of  this 
place  be  struck  off  the  repeal  list,  with  no  exception  but  that  of  the 

II 2 


164  GEORGE   BIDDELL  AIRY. 

parish  priest  who  was  proved  to  be  absent.  And  O'Connell  declares 
that  he  will  not  pass  through  this  place.  Now  for  my  journey.  It 
is  a  sort  of  half-mountain  country  all  the  way,  with  some  bogs  to 
refresh  my  eyes.  . 

VALENCIA  HOTEL, 

1843,  August  6. 

It  seems  that  my  coming  here  has  caused  infinite  alarm.  The 
common  people  do  not  know  what  to  conjecture,  but  have  some 
notion  that  the  "  sappers  and  miners  "  are  to  build  a  bridge  to  admit 
the  charge  of  cavalry  into  the  island.  An  attendant  of  Mrs  Fitz- 
gerald expressed  how  strange  it  was  that  a  man  looking  so  mild  and 
gentle  could  meditate  such  things  "  but  never  fear,  Maam,  those  that 
look  so  mild  are  always  the  worst "  :  then  she  narrated  how  that  her 
husband  was  building  some  stables,  but  that  she  was  demanding  of 
him  "  Pat,  you  broth  of  a  boy,  what  is  the  use  of  your  building  stables 
when  these  people  are  coming  to  destroy  everything."  I  suspect  that 
the  people  who  saw  me  walking  up  through  the  storm  yesterday  must 
have  thought  me  the  prince  of  the  powers  of  the  air  at  least. 


HIBERNIAN  HOTEL,  TRALEE, 

1843,  August  7. 

I  sailed  from  Valencia  to  Cahersiveen  town  in  a  sail-boat  up  the 
water  (not  crossing  at  the  ferry).  I  had  accommodated  my  time  to 
the  wish  of  the  boatman,  who  desired  to  be  there  in  time  for  prayers  : 
so  that  I  had  a  long  waiting  at  Cahersiveen  for  the  mail  car.  In 
walking  through  the  little  town,  I  passed  the  chapel  (a  convent 
chapel)  to  which  the  people  were  going :  and  really  the  scene  was 
very  curious.  The  chapel  appeared  to  be  overflowing  full,  and  the 
court  in  front  of  it  was  full  of  people,  some  sitting  on  the  ground, 
some  kneeling,  and  some  prostrate.  There  were  also  people  in  the 
street,  kneeling  with  their  faces  towards  the  gate  pillars,  &c.  It 
seemed  to  me  that  the  priest  and  the  chapel  were  of  less  use  here 
than  even  in  the  continental  churches,  and  I  do  not  see  why  both 
parties  should  not  have  stopped  at  home.  When  the  chapel  broke 
up,  it  seemed  as  if  the  streets  were  crammed  with  people.  The  turn- 
out that  even  a  small  village  in  Ireland  produces  is  perfectly  amazing. 


AT  GREENWICH   OBSERVATORY.  165 


1844 

"In  the  course  of  1843  I  had  put  in  hand  the  engraving 
of  the  drawings  of  the  Northumberland  Telescope  at  Cam- 
bridge Observatory,  and  wrote  the  description  for  letter- 
press. In  the  course  of  1844  the  work  was  completed,  and 
the  books  were  bound  and  distributed. 

"  The  building  to  receive  the  Altazimuth  Instrument  was 
erected  in  the  course  of  the  year;  during  the  construction  a 
foreman  fell  into  the  foundation  pit  and  broke  his  leg,  of 
which  accident  he  died.  This  is  the  only  accident  that  I 
have  known  at  the  Observatory. — The  Electrometer  Mast 
and  sliding  frame  were  erected  near  the  Magnetic  Observa- 
tory.— The  six-year  Catalogue  of  1439  stars  was  finished ; 
this  work  had  been  in  progress  during  the  last  few  years. — In 
May  I  went  to  Woolwich  to  correct  the  compasses  of  the 
'  Dover/  a  small  iron  steamer  carrying  mails  between  Dover 
and  Ostend  :  this  I  believe  was  the  first  iron  ship  possessed 
by  the  Admiralty. — The  Lunar  Reductions  were  making 
good  progress;  16  computers  were  employed  upon  them. 
I  made  application  for  printing  them  and  the  required  sum 
(;£iooo)  was  granted  by  the  Treasury. — In  this  year  com- 
menced that  remarkable  movement  which  led  to  the  dis- 
covery of  Neptune.  On  Feb.  I3th  Prof.  Challis  introduced 
Mr  Adams  to  me  by  letter.  On  Feb.  i$th  I  sent  my  ob- 
served places  of  Uranus,  which  were  wanted.  On  June 
1 9th  I  also  sent  places  to  Mr  E.  Bouvard. — As  regards 
the  National  Standards,  Mr  Baily  (who  undertook  the  com- 
parisons relating  to  standards  of  length)  died  soon,  and 
Mr  Sheepshanks  then  undertook  the  work. — I  attended  the 
meeting  of  the  British  Association  held  at  York  (principally 
in  compliment  to  the  President,  Dr  Peacock),  and  gave  an 
oral  account  of  my  work  on  Irish  Tides. — At  the  Oxford 
Commemoration  in  June,  the  honorary  degree  of  D.C.L.  was 
conferred  on  M.  Struve  and  on  me,  and  then  a  demand  was 


1 66  GEORGE  BIDDELL  AIRY. 

made  on  each  of  us  for  £6.  6s.  for  fees.  We  were  much 
disgusted  and  refused  to  pay  it,  and  1  wrote  angrily  to 
Dr  Wynter,  the  Vice-Chancellor.  The  fees  were  ultimately 
paid  out  of  the  University  Chest:- 

"  In  this  year  the  longitude  of  Altona  was  determined -by 
M.  Struve  for  the  Russian  Government.  For  this  purpose 
it  was  essential  that  facilities  should  be  given  for  landing 
chronometers  at  Greenwich.  But  the  consent  of  the  custom- 
house authorities  had  first  to  be  obtained,  and  this  required 
a  good  deal  of  negotiation.  Ultimately  the  determination 
was  completed  in  the  most  satisfactory  manner.  The  chro- 
nometers, forty-two  in  number,  crossed  the  German  Sea  six- 
teen times.  The  transit  observers  were  twice  interchanged, 
in  order  to  eliminate  not  only  their  Personal  Equation,  but 
also  the  gradual  change  of  Personal  Equation.  On  Sept. 
3Oth  Otto  Struve  formally  wrote  his  thanks  for  assistance 
rendered. 

"For  the  determination  of  the  longitude  of  Valencia,  which 
was  carried  out  in  this  year,  various  methods  were  discussed, 
but  the  plan  of  sending  chronometers  by  mail  conveyance 
was  finally  approved.  From  London  to  Liverpool  the  chro- 
nometers were  conveyed  by  the  railways,  from  Liverpool  to 
Kingstown  by  steamer,  from  Dublin  to  Tralee  by  the  Mail 
Coaches,  from  Tralee  to  Cahersiveen  by  car,  from  Cahersi- 
veen  to  Knightstown  by  boat,  and  from  Knightstown  to  the 
station  on  the  hill  the  box  was  carried  like  a  sedan-chair. 
There  were  numerous  other  arrangements,  and  all  succeeded 
perfectly  without  a  failure  of  any  kind.  Thirty  pocket  chro- 
nometers traversed  the  line  between  Greenwich  and  Kings- 
town about  twenty-two  times,  and  that  between  Kingstown 
and  Valencia  twenty  times.  The  chronometrical  longitudes 
of  Liverpool  Observatory,  Kingstown  Station,  and  Valencia 
Station  are  I2m  ox>5s,  24™  3i'i7s,  41™  23-25*;  the  geodetic 
longitudes,  computed  from  elements  which  I  published 
long  ago  in  the  Encyclopaedia  Metropolitana,  are  I2m  O'34S, 
24m  3 1 '47s,  4im  23'o6s.  It  appears  from  this  that  the  ele- 


AT   GREENWICH   OBSERVATORY.  167 

ments  to  which  I  have  alluded  represent  the  form  of  the 
Earth  here  as  nearly  as  is  possible.  On  the  whole,  I  think 
it  probable  that  this  is  the  best  arc  of  parallel  that  has  ever 
been  measured. 

"With  regard  to  the  Maine  Boundary:  on  May  7th 
Col.  Estcourt,  the  British  Commissioner,  wrote  to  me  de- 
scribing the  perfect  success  of  following  out  my  plan  :  the 
line  of  64  miles  was  cut  by  directions  laid  out  at  the  two 
ends,  and  the  cuttings  met  within  341  feet.  The  country 
through  which  this  line  was  to  pass  is  described  as  sur- 
passing in  its  difficulties  the  conception  of  any  European. 
It  consists  of  impervious  forests,  steep  ravines,  and  dismal 
swamps.  A  survey  for  the  line  was  impossible,  and  a  tenta- 
tive process  would  have  broken  the  spirit  of  the  best  men. 
I  therefore  arranged  a  plan  of  operations  founded  on  a 
determination  of  the  absolute  latitudes  and  the  difference 
of  longitudes  of  the  two  extremities.  The  difference  of 
longitudes  was  determined  by  the  transfer  of  chronometers 
by  the  very  circuitous  route  from  one  extremity  to  the 
other;  and  it  was  necessary  to  divide  the  whole  arc  into 
four  parts,  and  to  add  a  small  part  by  measure  and  bearing. 
When  this  was  finished,  the  azimuths  of  the  line  for  the  two 
ends  were  computed,  and  marks  were  laid  off  for  starting 
with  the  line  from  both  ends.  One  party,  after  cutting  more 
than  forty-two  miles  through  the  woods,  were  agreeably  sur- 
prised, on  the  brow  of  a  hill,  at  seeing  directly  before  them 
a  gap  in  the  woods  on  the  next  line  of  hill ;  it  opened 
gradually,  and  proved  to  be  the  line  of  the  opposite  party. 
On  continuing  the  lines  till  they  passed  abreast  of  each 
other,  their  distance  was  found  to  be  341  feet.  To  form 
an  estimate  of  the  magnitude  of  this  error,  it  is  to  be 
observed  that  it  implies  an  error  of  only  a  quarter  of  a 
second  of  time  in  the  difference  of  longitudes  ;  and  that  it 
is  only  one-third  (or  nearly  so)  of  the  error  which  would 
have  been  committed  if  the  spheroidal  form  of  the  Earth 
had  been  neglected.  I  must  point  out  the  extraordinary 


1 68  GEORGE  BIDDELL  AIRY. 

merit  of  the  officers  who  effected  this  operation.  Transits 
were  observed  and  chronometers  were  interchanged  when 
the  temperature  was  lower  than  19°  below  zero :  and  when 
the  native  assistants,  though  paid  highly,  deserted  on  ac- 
count of  the  severity  of  the  weather,  the  British  officers  still 
continued  the  observations  upon  whose  delicacy  everything 
depended. 

"Of  private  history:  From  July  3rd  to  Aug.  I3th  I  was  in 
Ireland  with  my  wife.  This  was  partly  a  business  journey 
in  connection  with  the  determination  of  the  longitude  of 
Valencia.  On  Jan.  4th  I  asked  Lord  Lyndhurst  (Lord 
Chancellor)  to  present  my  brother  to  the  living  of  Hel- 
mingham,  which  he  declined  to  do:  but  on  Dec.  I2th  he 
offered  Binbrooke,  which  I  accepted  for  my  brother." 


1845 

"  A  map  of  the  Buildings  and  Grounds  of  the  Observatory 
was  commenced  in  1844,  and  was  still  in  progress. — On 
Mar.  i gth  I  was  employed  on  a  matter  which  had  for  some 
time  occupied  my  thoughts,  viz.,  the  re-arrangement  of 
current  manuscripts.  I  had  prepared  a  sloping  box  (still  in 
use)  to  hold  24  portfolios  :  and  at  this  time  I  arranged  papers 
A,  and  went  on  with  B,  C,  &c.  Very  little  change  has  been 
made  in  these. — In  reference  to  the  time  given  to  the  weekly 
report  on  Meteorology  to  the  Registrar  General,  the  Report 
to  the  Board  of  Visitors  contains  the  following  paragraph  : 
'  The  devotion  of  some  of  my  assistants'  time  and  labour  to 
the  preparation  of  the  Meteorological  Report  attached  to  the 
weekly  report  of  the  Registrar  General,  is,  in  my  opinion, 
justified  by  the  bearing  of  the  meteorological  facts  upon  the 
medical  facts,  and  by  the  attention  which  I  understand  that 
Report  to  have  excited.' — On  Dec.  I3th  the  sleep  of  Astronomy 
was  broken  by  the  announcement  that  a  new  planet,  Astraea, 
was  discovered  by  Mr  Hencke.  I  immediately  circulated 
notices. — But  in  this  year  began  a  more  remarkable  planetary 


AT   GREENWICH   OBSERVATORY.  169 

discussion.  On  Sept.  22nd  Challis  wrote  to  me  to  say  that 
Mr  Adams  would  leave  with  me  his  results  on  the  explanation 
of  the  irregularities  of  Uranus  by  the  action  of  an  exterior 
planet.  In  October  Adams  called,  in  my  absence.  On 
Nov.  5th  I  wrote  to  him,  enquiring  whether  his  theory  ex- 
plained the  irregularity  of  radius-vector  (as  well  as  that  of 
longitude).  I  waited  for  an  answer,  but  received  none. 
(See  the  Papers  printed  in  the  Royal  Astronomical  Society's 
Memoirs  and  Monthly  Notices). — In  the  Royal  Society,  the 
Royal  Medal  was  awarded  to  me  for  my  Paper  on  the  Irish 
Tides. — In  the  Royal  Astronomical  Society  I  was  President ; 
and,  with  a  speech,  delivered  the  Medal  to  Capt.  Smyth  for 
the  Bedford  Catalogue  of  Double  Stars. — On  Jan.  2ist  I  was 
appointed  (with  Schumacher)  one  of  the  Referees  for  the  King 
of  Denmark's  Comet  Medal :  I  have  the  King's  Warrant  under 
his  sign  manual. — The  Tidal  Harbour  Commission  com- 
menced on  Apr.  5th:  on  July  2 1st  my  Report  on  Wexford 
Harbour  (in  which  I  think  I  introduced  important  principles) 
was  communicated.  One  Report  was  made  this  year  to  the 
Government. — In  the  matter  of  Saw  Mills  (which  had  begun 
in  1842),  I  had  prepared  a  second  set  of  plans  in  1844,  and  in 
this  year  Mr  Nasmyth  made  a  very  favourable  report  on  my 
plan.  A  machinist  of  the  Chatham  Dock  Yard,  Sylvester, 
was  set  to  work  (but  not  under  my  immediate  command)  to 
make  a  model  :  and  this  produced  so  much  delay  as  ulti- 
mately to  ruin  the  design. —  On  Jan.  1st  I  was  engaged  on  my 
Paper  '  On  the  flexure  of  a  uniform  bar,  supported  by  equal 
pressures  at  equidistant  points.'  "  (This  was  probably  in  con- 
nection with  the  support  of  Standards  of  Length,  for  the 
Commission.  Ed.). — In  June  I  attended  the  Meeting  of  the 
British  Association  at  Cambridge,  and  on  the  2Oth  I  gave  a 
Lecture  on  Magnetism  in  the  Senate  House.  The  following 
quotation  relating  to  this  Lecture  is  taken  from  a  letter  by 
Whewell  to  his  wife  (see  Life  of  William  Whewell  by  Mrs 
Stair  Douglas) :  "  I  did  not  go  to  the  Senate  House  yester- 
day evening.  Airy  was  the  performer,  and  appears  to  have 


L7O  GEORGE   BIDDELL   AIRY. 

outdone  himself  in  his  art  of  giving  clearness  and  simplicity 
to  the  hardest  and  most  complex  subjects.  He  kept  the 
attention  of  his  audience  quite  enchained  for  above  two 
hours,  talking  about  terrestrial  magnetism." — On  Nov.  29th 
I  gave  evidence  before  a  Committee  of  the  House  of  Com- 
mons on  Dover  Harbour  Pier. 

"  With  respect  to  the  Magnetical  and  Meteorological  Estab- 
lishment, the  transactions  in  this  year  were  most  important. 
It  had  been  understood  that  the  Government  establishments 
had  been  sanctioned  twice  for  three-year  periods,  of  which  the 
second  would  expire  at  the  end  of  1845  :  ano^  it  was  a  ques- 
tion with  the  scientific  public  whether  they  should  be  con- 
tinued. My  own  opinion  was  in  favour  of  stopping  the 
observations  and  carefully  discussing  them.  And  I  am 
convinced  that  this  would  have  been  best,  except  for  the 
subsequent  introduction  of  self-registering  systems,  in  which 
I  had  so  large  a  share.  There  was  much  discussion  and  cor- 
respondence, and  on  June  /th  the  Board  of  Visitors  resolved 
that  '  In  the  opinion  of  the  Visitors  it  is  of  the  utmost  im- 
portance that  these  observations  should  continue  to  be  made 
on  the  most  extensive  scale  which  the  interests  of  those 
sciences  may  require.'  The  meeting  of  the  British  Associa- 
tion was  held  at  Cambridge  in  June  :  and  one  of  the  most 
important  matters  there  was  the  Congress  of  Magnetic 
Philosophers,  many  of  them  foreigners.  It  was  resolved 
that  the  Magnetic  Observatory  at  Greenwich  be  continued 
permanently.  At  this  meeting  I  proposed  a  resolution  which 
has  proved  to  be  exceedingly  important.  I  had  remarked 
the  distress  which  the  continuous  two-hourly  observations 
through  the  night  produced  to  my  Assistants,  and  determined 
if  possible  to  remove  it.  I  therefore  proposed  *  That  it  is 
highly  desirable  to  encourage  by  specific  pecuniary  reward 
the  improvement  of  self-recording  rnagnetical  and  meteoro- 
logical apparatus  :  and  that  the  President  of  the  British 
Association  and  the  President  of  the  Royal  Society  be 
requested  to  solicit  the  favourable  consideration  of  Her 


AT   GREENWICH   OBSERVATORY.  171 

Majesty's  Government  to  this  subject/  which  was  adopted. 
In  October  the  Admiralty  expressed  their  willingness  to 
grant  a  reward  up  to  £500.  Mr  Charles  Brooke  had  written 
to  me  proposing  a  plan  on  Sept.  23rd,  and  he  sent  me  his 
first  register  on  Nov.  24th.  On  Nov.  1st  the  Treasury  in- 
formed the  Admiralty  that  the  Magnetic  Observatories  will 
be  continued  for  a  further  period. 

"  The  Railway  Gauge  Commission  in  this  year  was  an 
important  employment.  The  Railways,  which  had  begun 
with  the  Manchester  and  Liverpool  Railway  (followed  by  the 
London  and  Birmingham)  had  advanced  over  the  country 
with  some  variation  in  their  breadth  of  gauge.  The  gauge  of 
the  Colchester  Railway  had  been  altered  to  suit  that  of  the 
Cambridge  Railway.  And  finally  there  remained  but  two 
gauges  :  the  broad  gauge  (principally  in  the  system  allied 
with  the  Great  Western  Railway);  and  the  narrow  gauge 
(through  the  rest  of  England).  These  came  in  contact  at 
Gloucester,  and  were  likely  to  come  in  contact  at  many  other 
points — to  the  enormous  inconvenience  of  the  public.  The 
Government  determined  to  interfere,  beginning  with  a  Com- 
mission. On  July  3rd  Mr  Laing  (then  on  the  Board  of 
Trade)  rode  to  Greenwich,  bearing  a  letter  of  introduction 
from  Sir  John  Lefevre  and  a  request  from  Lord  Dalhousie 
(President  of  the  Board  of  Trade)  that  I  would  act  as  second 
of  a  Royal  Commission  (Col.  Sir  Frederick  Smith,  Airy,  Prof. 
Barlow).  I  assented  to  this :  and  very  soon  began  a  vigorous 
course  of  business.  On  July  23rd  and  24th  I  went  with  Prof. 
Barlow  and  our  Secretary  to  Bristol,  Gloucester,  and  Birming- 
ham :  on  Dec.  I7th  I  went  on  railway  experiments  to  Didcot : 
and  on  Dec.  2pth  to  Jan.  2nd  I  went  to  York,  with  Prof. 
Barlow  and  George  Arthur  Biddell,  for  railway  experiments. 
On  Nov.  2 ist  I  finished  a  draft  Report  of  the  Railway  Gauge 
Commission,  which  served  in  great  measure  as  a  basis  for  that 
adopted  next  year. 

"  Of  private  history  :  I  wrote  to  Lord  Lyndhurst  on  Feb. 
2Oth,  requesting  an  exchange  of  the  living  to  which  he  had 


1/2  GEORGE  BIDDELL  AIRY. 

presented  my  brother  in  Dec.  1844  for  that  of  Swineshead  :  to 
which  he  consented. — On  Jan.  2Qth  I  went  with  my  wife  on  a 
visit  to  my  uncle  George  Biddell,  at  Bradfield  St  George,  near 
Bury. — On  June  Qth  I  went  into  th&  mining  district  of  Cornwall 
with  George  Arthur  Biddell. — From  Aug.  25th  to  Sept.  26th 
I  was  travelling  in  France  with  my  sister  and  my  wife's  sister, 
Georgiana  Smith.  I  was  well  introduced,  arid  the  journey 
was  interesting. — On  Oct.  2Qth  my  son  Osmund  was  born. — 
Mr  F.  Baily  bequeathed  to  me  £500,  which  realized  £450." 

Here  are  some  extracts  from  letters  written  to  his  wife 
relating  to  the  visit  to  the  Cornish  mines,  &c. — 

PEARCE'S  HOTEL,  FALMOUTH, 
1845,  June  I2//&,   Thursday. 

Then  we  walked  to  the  United  Mines  in  Gwennap.  The  day 
was  very  fine  and  now  it  was  perfectly  broiling :  and  the  hills  here 
are  long  and  steep.  At  the  United  Mines  we  found  the  Captain, 
and  he  invited  us  to  join  in  a  rough  dinner,  to  which  he  and  the 
other  captains  were  going  to  sit  down.  Then  we  examined  one  of 
the  great  pumping  engines,  which  is  considered  the  best  in  the 
country:  and  some  other  engines.  Between  3  and  4  there  was  to 
be  a  setting  out  of  some  work  to  the  men  by  a  sort  of  Dutch  Auction 
(the  usual  way  of  setting  out  the  work  here) :  some  refuse  ores  were 
to  be  broken  up  and  made  marketable,  and  the  subject  of  competi- 
tion was,  for  how  little  in  the  pound  on  the  gross  produce  the  men 
would  work  them  up.  While  we  were  here  a  man  was  brought  up 
who  was  hurt  in  blasting :  a  piece  of  rock  had  fallen  on  him.  At  this 
mine  besides  the  ladder  ways,  they  have  buckets  sliding  in  guides  by 
which  the  men  are  brought  up:  and  they  are  just  preparing  for  work 
another  apparatus  which  they  say  is  tried  successfully  at  another 
mine  (Tresavean) :  there  are  two  wooden  rods  A  and  B  reaching  from 
the  top  to  the  bottom,  moved  by  cranks  from  the  same  wheel,  so  that 
one  goes  up  when  the  other  goes  down,  and  vice  versa:  each  of 
these  rods  has  small  stages,  at  such  a  distance  that  when  the  rod  A 
is  down  and  the  rod  B  is  up,  the  first  stage  of  A  is  level  with  the 
first  stage  of  B\  but  when  the  rod  A  is  up  and  the  rod  B  is  down, 
the  second  stage  of  A  is  level  with  the  first  stage  of  B :  so  a  man 
who  wants  to  descend  steps  on  the  first  stage  of  A  and  waits  till  it 
goes  down:  then  he  steps  sideways  on  the  first  stage  of  B  and  waits 


AT  GREENWICH   OBSERVATORY.  173 

till  it  goes  down :  then  he  steps  sideways  to  the  second  stage  of  A 
and  waits  till  it  goes  down,  and  so  on :  or  if  a  man  is  coming  up  he 
does  just  the  same.  While  we  were  here  Mr  R.  Taylor  came.  We 
walked  home  (a  long  step,  perhaps  seven  miles)  in  a  very  hot  sun. 
Went  to  tea  to  Mr  Alfred  Fox,  who  has  a  house  in  a  beautiful 
position  looking  to  the  outside  of  Falmouth  Harbour. 


PENZANCE, 
1845,  June  14,  Satitrday. 

Yesterday  morning  we  breakfasted  early  at  Falmouth,  and  before 
9  started  towards  Gwennap.  I  had  ascertained  on  Thursday  that 
John  Williams  (the  senior  of  a  very  wealthy  and  influential  family  in 
this  country)  was  probably  returned  from  London.  So  we  drove  first 
to  his  house  Burntcoose  or  Barncoose,  and  found  him  and  his  wife 
at  home.  (They  are  Quakers,  the  rest  of  the  family  are  not.)  Sedg- 
wick,  and  Whewell,  and  I,  or  some  of  our  party  including  me,  had  slept 
once  at  their  house.  They  received  George  and  me  most  cordially,  and 
pressed  us  to  come  and  dine  with  them  after  our  visit  to  Tresavean 
mine,  of  which  intention  I  spoke  in  my  last  letter:  so  I  named 
4  o'clock  as  hour  for  dinner.  After  a  little  stay  we  drove  to 
Tresavean,  where  I  found  the  Captain  of  the  mine  prepared  to  send 
an  Underground  Captain  and  a  Pit-man  to  descend  with  us.  So  we 
changed  our  clothes  and  descended  by  the  ladders  in  the  pumpshaft. 
Pretty  work  to  descend  with  the  huge  pump-rods  (garnished  with 
large  iron  bolts)  working  violently,  making  strokes  of  12  feet,  close  to 
our  elbows;  and  with  a  nearly  bottomless  pit  at  the  foot  of  every 
ladder,  where  we  had  to  turn  round  the  foot  of  the  ladder  walking 
on  only  a  narrow  board.  However  we  got  down  to  the  bottom  of 
the  mine  with  great  safety  and  credit,  seeing  all  the  mighty 
machinery  on  the  way,  to  a  greater  depth  than  I  ever  reached 
before,  namely  1900  feet.  From  the  bottom  of  the  pump  we  went 
aside  a  short  distance  into  the  lowest  workings  where  two  men 
nearly  naked  were  driving  a  level  towards  the  lode  or  vein  of  ore. 
Here  I  felt  a  most  intolerable  heat :  and  upon  moving  to  get  out  of 
the  place,  I  had  a  dreadful  feeling  of  feebleness  and  fainting,  such 
as  I  never  had  in  my  life  before.  The  men  urged  me  to  climb  the 
ladders  to  a  level  where  the  air  was  better,  but  they  might  as  well 
have  urged  me  to  lift  up  the  rock.  I  could  do  nothing  but  sit  down 
and  lean  fainting  against  the  rocks.  This  arose  entirely  from  the 


174  GEORGE   BIDDELL   AIRY. 

badness  of  the  air.  After  a  time  I  felt  a  trifle  better,  and  then  I 
climbed  one  short  ladder,  and  sat  down  very  faint  again.  When  I 
recovered,  two  men  tied  a  rope  round  me,  and  went  up  the  ladder 
before  me,  supporting  a  .part  of  my  weight,  and  in  this  way  I 
ascended  four  or  five  ladders  (with  lorig  rests  between)  till  we  came 
to  a  level,  260  fathoms  below  the  adit  or  nearly  300  fathoms  below 
the  surface,  where  there  was  a  tolerable  current  of  pretty  good  air. 
Here  I  speedily  recovered,  though  I  was  a  little  weak  for  a  short 
time  afterwards.  George  also  felt  the  bad  air  a  good  deal,  but  not 
so  much  as  I.  He  descended  to  some  workings  equally  low  in 
another  place  (towards  which  the  party  that  I  spoke  of  were  directing 
their  works),  but  said  that  the  air  there  was  by  no  means  so  bad. 
We  all  met  at  the  bottom  of  the  man-engine  260  fathoms  below  the 
adit.  We  sat  still  a  little  while,  and  I  acquired  sufficient  strength 
and  nerve,  so  that  I  did  not  feel  the  slightest  alarm  in  the  operation 
of  ascending  by  the  man-engine.  This  is  the  funniest  operation  that  I 
ever  saw  :  it  is  the  only  absolute  novelty  that  I  have  seen  since  I  was 
in  the  country  before  :  it  has  been  introduced  2  J  years  in  Tresavean, 
and  one  day  in  the  United  Mines.  In  my  last  letter  I  described 
the  principle.  In  the  actual  use  there  is  no  other  motion  to  be  made 
by  the  person  who  is  ascending  or  descending  than  that  of  stepping 
sideways  each  time  (there  being  proper  hand-holds)  with  no  exertion 
at  all,  except  that  of  stepping  exactly  at  the  proper  instant :  and  not 
the  shadow  of  unpleasant  feeling  in  the  motion.  Any  woman  may 
go  with  the  most  perfect  comfort,  if  she  will  but  attend  to  the  rules 
of  stepping,  and  forget  that  there  is  an  open  pit  down  to  the  very 
bottom  of  the  mine.  In  this  way  we  were  pumped  up  to  the  surface, 
and  came  up  as  cool  as  cucumbers,  instead  of  being  drenched  with 
perspiration.  In  my  description  in  last  letter  I  forgot  to  mention 
that  between  the  stages  on  the  moving  rods  which  I  have  there 
described  there  are  intermediate  stages  on  the  moving  rods  (for 
which  there  is  ample  room,  inasmuch  as  the  interval  between  the 
stages  on  each  rod  used  by  one  person  is  24  feet),  and  these  inter- 
mediate stages  are  used  by  persons  descending-,  so  that  there  are 
persons  ascending  and  persons  descending  at  the  same  time,  who  never 
interfere  with  each  other  and  never  step  on  the  same  stages,  but  merely 
see  each  other  passing  on  the  other  rods. — It  is  a  most  valuable  in- 
vention. We  then  changed  our  clothes  and  washed,  and  drove  to 
Barncoose,  arriving  in  good  time  for  the  dinner.  I  found  myself  much 
restored  by  some  superb  Sauterne  with  water.  When  we  were  pro- 
posing to  go  on  to  Camborne,  Mr  and  Mrs  Williams  pressed  us  so 


AT   GREENWICH   OBSERVATORY.  175 

affectionately  to  stop  that  we  at  length  decided  on  stopping  for  the 
night,  only  bargaining  for  an  early  breakfast  this  morning.  This 
morning  after  breakfast,  we  started  for  Redruth  and  Camborne.  The 
population  between  them  has  increased  immensely  since  I  was  here 
before.  &c.  &c. 


Here  is  a  letter  written  to  his  wife  while  he  was  engaged 
on  the  business  of  the  Railway  Gauge  Commission.  It  con- 
tains reminiscences  of  some  people  who  made  a  great  figure 
in  the  railway  world  at  that  time,  and  was  preceded  by  a 
letter  which  was  playfully  addressed  "  From  the  Palace  of 
King  Hudson,  York." 

GEORGE  INN,  YORK, 

1845,  Dec.  30. 

I  wrote  yesterday  from  Mr  Hudson's  in  time  for  the  late  post, 
and  hope  that  my  letter  might  be  posted  by  the  servant  to  whom  it 
was  given.  Our  affairs  yesterday  were  simple :  we  reached  Euston 
Station  properly,  found  Watson  there,  found  a  carriage  reserved  for 
us,  eat  pork-pie  at  Wolverton  (not  so  good  as  formerly),  dined  at 
Derby,  and  arrived  in  York  at  5.20.  On  the  way  Watson  informed 
me  that  the  Government  have  awarded  us  .£500  each.  Sir  F.  Smith 
had  talked  over  the  matter  with  us,  and  I  laid  it  down  as  a  principle 
that  we  considered  the  business  as  an  important  one  and  one  of  very 
great  responsibility,  and  that  we  wished  either  that  the  Government 
should  treat  us  handsomely  or  should  consider  us  as  servants  of  the 
State  acting  gratuitously,  to  which  they  assented.  I  think  the 
Government  have  done  very  well.  Mr  Hudson,  as  I  have  said,  met 
us  on  the  platform  and  pressed  us  to  dine  with  him  (though  I  had 
dined  twice).  Then  we  found  the  rival  parties  quarrelling,  and  had 
to  arrange  between  them.  This  prevented  me  from  writing  for  the 
early  post.  (I  forgot  to  mention  that  Saunders,  the  Great  Western 
Secretary,  rode  with  us  all  the  way).  At  Hudson's  we  had  really  a 
very  pleasant  dinner:  I  sat  between  Vernon  Harcourt  and  Mrs 
Malcolm  (his  sister  Georgiana)  and  near  to  Mr  Hudson.  This  morn- 
ing we  were  prepared  at  9  at  the  Station  for  some  runs.  Brunei  and 
other  people  had  arrived  in  the  night.  And  we  have  been  to 
Darlington  and  back,  with  a  large  party  in  our  experimental  train. 
George  Arthur  Biddell  rode  on  the  engine  as  representing  me.  But 
the  side  wind  was  so  dreadfully  heavy  that,  as  regards  the  wants  of  the 


176  GEORGE   BIDDELL  AIRY. 

case,  this  day  is  quite  thrown  away.  We  have  since  been  to  lunch 
with  Vernon  Harcourt  (Mrs  Harcourt  not  at  home)  and  then  went 
with  him  to  look  at  the  Cathedral.  The  Chapter-house,  which  was  a 
little  injured,  has  been  pretty  well  restored  :  all  other  things  in  good 
order.  The  Cathedral  looks  smaller  and  lower  than  French 
cathedrals.  Now  that  we  have  come  in,  the  Lord  Mayor  of  York 
has  just  called  to  invite  us  to  dinner  to-morrow. — I  propose  to 
George  Arthur  Biddell  that  he  go  to  Newcastle  this  evening,  in  order 
to  see  glass  works  and  other  things  there  to-morrow,  and  to  return 
when  he  can. 

I  think  that  I  can  persuade  Barlow  to  stop  to  see  the  experiments 
out,  and  if  so  I  shall  endeavour  to  return  as  soon  as  possible.  The 
earliest  day  would  be  the  day  after  to-morrow. 


The  following  extract  is  from  a  letter  written  to  Mr 
Murray  for  insertion  in  his  Handbook  of  France,  relating  to 
the  Breakwater  at  Cherbourg,  which  Airy  had  visited  during 
his  journey  in  France  in  the  autumn  of  this  year. 

ROYAL  OBSERVATORY,  GREENWICH, 

1845,  Oct.  %th. 

My  opinion  on  the  construction  I  need  not  say  ought  not  to  be 
quoted  :  but  you  are  quite  welcome  to  found  any  general  statement 
on  it ;  or  perhaps  it  may  guide  you  in  further  enquiries.  To  make  it 
clear,  I  must  speak  rather  generally  upon  the  subject.  There  are 
three  ways  in  which  a  breakwater  may  be  constructed.  i.  By 
building  a  strong  wall  with  perpendicular  face  from  the  bottom  of 
the  sea.  2.  By  making  a  bank  with  nothing  but  slopes  towards  the 
sea.  3.  By  making  a  sloping  bank  to  a  certain  height  and  then 
building  a  perpendicular  wall  upon  it. — Now  if  the  ist  of  these  con- 
structions could  be  arranged,  I  have  no  doubt  that  it  would  be  the 
best  of  all,  because  a  sea  does  not  break  against  a  perpendicular  face, 
but  recoils  in  an  unbroken  swell,  merely  making  a  slow  quiet  push  at 
the  wall,  and  not  making  a  violent  impact.  But  practically  it  is  nearly 
impossible.  The  2nd  construction  makes  the  sea  to  break  tremen- 
dously, but  if  the  sloping  surface  be  made  of  square  stone  put  together 
with  reasonable  care  there  is  not  the  smallest  tendency  to  unseat 
these  stones.  This  is  the  principle  of  construction  of  Plymouth 
Breakwater.  In  the  3rd  construction,  the  slope  makes  the  sea 
to  break  tremendously,  and  then  it  strikes  the  perpendicular  face 


AT   GREENWICH   OBSERVATORY.  177 

with  the  force  of  a  battering  ram  :  and  therefore  in  my  opinion  this 
is  the  worst  construction  of  all.  A  few  face-stones  may  easily  be 
dislodged,  and  then  the  sea  entering  with  this  enormous  force  will 
speedily  destroy  the  whole.  This  is  the  form  of  the  Cherbourg 
Digue. 

From  this  you  will  gather  that  I  have  a  full  belief  that  Plymouth 
Breakwater  will  last  very  long,  and  that  the  Digue  of  Cherbourg,  at 
least  its  upper  wall,  will  not  last  long.  The  great  bank  will  last  a 
good  while,  gradually  suffering  degradation,  but  still  protecting  the 
Road  pretty  well. 

I  was  assured  by  the  officers  residing  on  the  Digue  that  the  sea 
which  on  breaking  is  thrown  vertically  upwards  and  then  falls  down 
upon  the  pavement  does  sometimes  push  the  stones  about  which  are 
lying  there  and  which  weigh  three  or  four  tons. 

I  saw  some  preparations  for  the  foundations  of  the  fort  at  the 
eastern  extremity  of  the  Digue.  One  artificial  stone  of  concrete 
measured  12''$"  x  6''7"  x  $''?",  and  was  estimated  to  weigh  25000 
kilogrammes. 


A.  B.  12 


CHAPTER    VI. 
AT  GREENWICH  OBSERVATORY— 1846  TO  1856. 

1846 

"  ON  Nov.  /th  I  proposed  a  change  in  the  form  of 
Estimates  for  the  Observatory.  The  original  astronomical 
part  was  provided  by  the  Admiralty,  and  the  new  mag- 
netical  and  meteorological  part  was  provided  by  the 
Treasury :  and  the  whole  Estimates  and  Accounts  of  the 
Observatory  never  appeared  in  one  public  paper.  I  pro- 
posed that  the  whole  should  be  placed  on  the  Navy  Esti- 
mates, but  the  Admiralty  refused.  I  repeated  this  in  sub- 
sequent years,  with  no  success.  Meantime  I  always  sent  to 
the  Admiralty  a  duplicate  of  my  Treasury  Estimate  with  the 
proper  Admiralty  Estimate. — Stephenson's  Railway  through 
the  lower  part  of  the  Park,  in  tunnel  about  850  feet  from  the 
Observatory,  was  again  brought  forward.  On  Feb.  2Oth  it 
was  put  before  me  by  the  Government,  and  on  March  9th  I 
made  experiments  at  Kensal  Green,  specially  on  the  effect  of 
a  tunnel :  which  I  found  to  be  considerable  in  suppressing  the 
tremors.  On  May  6th  I  made  my  Report,  generally  favour- 
able, supposing  the  railway  to  be  in  tunnel.  On  May  I3th  I, 
with  Mr  Stephenson,  had  an  interview  at  the  Admiralty  with 
Lord  Ellenborough  and  Sir  George  Cockburn.  The  Earl 
appeared  willing  to  relax  in  his  scruples  about  allowing  a 
railway  through  the  Park,  when  Sir  George  Cockburn  made  a 
most  solemn  protest  against  it,  on  the  ground  of  danger  to  an 
institution  of  such  importance  as  the  Observatory.  I  have  no 
doubt  that  this  protest  of  Sir  George  Cockburn's  really  deter- 


AT   GREENWICH   OBSERVATORY— 1846   TO    1856.         179 

mined  the  Government.  On  June  zoth  I  was  informed  that 
the  Government  refused  their  consent.  After  this  the  South 
Eastern  Railway  Company  adopted  the  line  through  Tranquil 
Vale. — In  consequence  of  the  defective  state  of  Paramatta 
Observatory  I  had  written  to  Sir  Robert  Peel  on  April  i6th 
raising  the  question  of  a  General  Superintending  Board  for 
Colonial  Observatories  :  and  on  June  27th  I  saw  Mr  Gladstone 
at  the  Colonial  Office  to  enquire  about  the  possibility  of  estab- 
lishing local  Boards.  On  June  2pth  a  general  plan  was 
settled,  but  it  never  came  to  anything. — Forty  volumes  of  the 
Observatory  MSS.  were  bound — an  important  beginning. — 
Deep-sunk  thermometers  were  prepared  by  Prof.  Forbes. — 
On  June  22nd  Sir  Robert  Inglis  procured  an  Order  of  the 
House  of  Commons  for  printing  a  paper  of  Sir  James  South's, 
ostensibly  on  the  effects  of  a  railway  passing  through  Green- 
wich Park,  but  really  attacking  almost  everything  that  I  did 
in  the  Observatory.  I  replied  to  this  on  July  2ist  by  a  letter 
in  the  Athenaeum  addressed  to  Sir  Robert  Inglis,  in  terms  so 
strong  and  so  well  supported  that  Sir  James  South  was 
effectually  silenced."  The  following  extract  from  a  letter  of 
Airy's  to  the  Earl  of  Rosse,  dated  Dec.  I5th  1846,  will  shew 
how  pronounced  the  quarrel  between  Airy  and  South  had 
become  in  consequence  of  the  above-mentioned  attack  and 
previous  differences :  "  After  the  public  exposure  which  his 
conduct  in  the  last  summer  compelled  me  to  make,  I  certainly 
cannot  meet  him  on  equal  terms,  and  desire  not  to  meet  him 
at  all."  (Ed.).—"  In  the  Mag.  and  Met.  Department,  I  was 
constantly  engaged  with  Mr  Charles  Brooke  in  the  prepara- 
tion and  mounting  of  the  self-registering  instruments,  and  the 
chemical  arrangements  for  their  use,  to  the  end  of  the  year. 
With  Mr  Ronalds  I  was  similarly  engaged :  but  I  had  the 
greatest  difficulty  in  transacting  business  with  him,  from  his 
unpractical  habits. — The  equipment  of  the  Liverpool  Obser- 
vatory, under  me,  was  still  going  on  :  I  introduced  the  use  of 
Siemens's  Chronometric  Governor  for  giving  horary  motion  to 
an  Equatoreal  there.  I  have  since  introduced  the  same  prin- 

12 — 2 


180  GEORGE   BIDDELL  AIRY. 

ciple  in  the  Chronograph  Barrel  and  the  Great  Equatoreal  at 
Greenwich  :  I  consider  it  important. — On  Feb.  I3th  I  received 
the  Astronomical  Society's  Medal  for  the  Planetary  Reduc- 
tions.— In  the  University  of  London  :  At  this  time  seriously 
began  the  discussion  whether  there  should  be  a  compulsory 
examination  in  matters  bearing  on  religious  subjects.  After 
this  there  was  no  peace. — For  discovery  of  "Comets  three 
medals  were  awarded  by  Schumacher  and  me :  one  to 
Peters,  two  to  De  Vico.  A  comet  was  seen  by  Hind,  and 
by  no  other  observer  :  after  correspondence,  principally  in 
1848,  the  medal  was  refused  to  him. — With  respect  to  the 
Railway  Gauge  Commission  :  On  Jan.  1st,  in  our  experi- 
ments near  York,  the  engine  ran  off  the  rails.  On  Jan.  2pth 
the  Commissioners  signed  the  Report,  and  the  business  was 
concluded  by  the  end  of  April.  Our  recommendation  was 
that  the  narrow  gauge  should  be  carried  throughout.  This 
was  opposed  most  violently  by  partisans  of  the  broad  gauge, 
and  they  had  sufficient  influence  in  Parliament  to  prevent  our 
recommendation  from  being  carried  into  effect.  But  the 
policy,  even  of  the  Great  Western  Railway  (in  which  the 
broad  gauge  originated),  has  supported  our  views  :  the  narrow 
gauge  has  been  gradually  substituted  for  the  broad  :  and  the 
broad  now  (1872)  scarcely  exists. — On  June  2Oth  Lord  Can- 
ning enquired  of  me  about  makers  for  the  clock  in  the  Clock 
Tower  of  Westminster  Palace.  I  suggested  Vulliamy,  Dent, 
Whitehurst ;  and  made  other  suggestions :  I  had  some  cor- 
respondence with  E.  B.  Denison,  about  clocks. — I  had  much 
correspondence  with  Stephenson  about  the  Tubular  Bridge 
over  the  Menai  Straits.  Stephenson  afterwards  spoke  of  my 
assistance  as  having  much  supported  him  in  this  anxious 
work:  on  Dec.  nth  I  was  requested  to  make  a  Report,  and 
to  charge  a  fee  as  a  Civil  Engineer  ;  but  I  declined  to  do  so. 
In  January  I  went,  with  George  Arthur  Biddell,  to  Portsmouth, 
to  examine  Lord  Dundonald's  rotary  engine  as  mounted  in  the 
'Janus,'  and  made  a  Report  on  the  same  to  the  Admiralty: 
and  I  made  several  subsequent  Reports  on  the  same  matter. 


AT   GREENWICH   OBSERVATORY — 1846   TO    1856.        l8l 

The  scheme  was  abandoned  in  the  course  of  next  year ;  the 
real  cause  of  failure,  as  I  believe,  was  in  the  bad  mounting  in 
the  ship. 

"  The  engrossing  subject  of  this  year  was  the  discovery  of 
Neptune.  As  I  have  said  (1845)  I  obtained  no  answer  from 
Adams  to  a  letter  of  enquiry.  Beginning  with  June  26th  of 
1846  I  had  correspondence  of  a  satisfactory  character  with 
Le  Verrier,  who  had  taken  up  the  subject  of  the  disturbance 
of  Uranus,  and  arrived  at  conclusions  not  very  different  from 
those  of  Adams.  I  wrote  from  Ely  on  July  gth  to  Challis, 
begging  him,  as  in  possession  of  the  largest  telescope  in  Eng- 
land, to  sweep  for  the  planet,  and  suggesting  a  plan.  I 
received  information  of  its  recognition  by  Galle,  when  I  was 
visiting  Hansen  at  Gotha.  For  further  official  history,  see  my 
communications  to  the  Royal  Astronomical  Society,  and  for 
private  history  see  the  papers  in  the  Royal  Observatory.  I 
was  abused  most  savagely  both  by  English  and  French." 

The  Report  to  the  Visitors  contains  an  interesting  account 
of  the  Great  Lunar  Reductions,  from  which  the  following 
passage  is  extracted  :  "  Of  the  Third  Section,  containing  the 
comparison  of  Observed  Places  with  Tabular  Places,  three 
sheets  are  printed,  from  1750  to  1756.  This  comparison,  it  is 
to  be  observed,  does  not  contain  a  simple  comparison  of 
places,  but  contains  also  the  coefficients  of  the  various 
changes  in  the  moon's  place  depending  on  changes  in  the 
elements.  .  .  .  The  process  for  the  correction  of  the  elements 
by  means  of  these  comparisons  is  now  going  on  :  and  the 
extent  of  this  work,  even  after  so  much  has  been  prepared, 
almost  exceeds  belief.  For  the  longitude,  ten  columns  are 
added  in  groups,  formed  in  thirteen  different  ways,  each 
different  way  having  on  the  average  about  nine  hundred 
groups.  For  the  ecliptic  polar  distance,  five  columns  are 
added  in  groups,  formed  in  seven  different  ways,  each 
different  way  having  on  the  average  about  nine  hundred 
groups.  Thus  it  will  appear  that  there  are  not  fewer  than 
150,000  additions  of  columns  of  figures.  This  part  of  the 


1 82  GEORGE   BIDDELL   AIRY. 

work  is  not  only  completed  but  is  verified,  so  that  the 
books  of  comparison  of  Observed  and  Tabular  Places  are, 
as  regards  this  work,  completely  cleared  out.  The  next  step 
is  to  take  the  means  of  these  groiips,  a  process  which  is  now 
in  hand :  it  will  be  followed  by  the  formation  and  solution  of 
the  equations  on  which  the  corrections  of  the  elements 
depend." 

The  following  remarks,  extracted  from  the  Report  to  the 
Visitors,  with  respect  to  the  instrumental  equipment  of  the 
Observatory,  embody  the  views  of  the  Astronomer  Royal  at 
this  time :  "  The  utmost  change,  which  I  contemplate  as 
likely  to  occur  in  many  years,  in  regard  to  our  meridional 
instruments,  is  the  substitution  of  instruments  of  the  same 
class  carrying  telescopes  of  larger  aperture.  The  only  in- 
strument which,. as  I  think,  may  possibly  be  called  for  by  the 
demands  of  the  astronomer  or  the  astronomical  public,  is  a 
telescope  of  the  largest  size,  for  the  observation  of  faint 
nebulae  and  minute  double  stars.  Whether  the  addition  of 
such  an  instrument  to  our  apparatus  would  be  an  advantage, 
is,  in  my  opinion,  not  free  from  doubt.  The  line  of  conduct 
for  the  Observatory  is  sufficiently  well  traced ;  there  can  be 
no  doubt  that  our  primary  objects  ought  to  be  the  accurate 
determination  of  places  of  the  fundamental  Stars,  the  Sun, 
the  Planets,  and,  above  all,  the  Moon.  Any  addition  what- 
ever to  our  powers  or  our  instrumental  luxuries,  which  should 
tend  to  withdraw  our  energies  from  these  objects,  would  be  a 
misfortune  to  the  Observatory." 

Of  private  history  :  "  In  March  I  visited  Prof.  Sedgwick  at 
Norwich. — On  Mar.  28th  the  '  Sir  Henry  Pottinger '  was 
launched  from  Fairbairn's  Yard  on  the  Isle  of  Dogs,  where  I 
was  thrown  down  and  dislocated  my  right  thumb. — From 
Apr.  10th  to  1 5th  I  was  at  Playford. — On  June  loth  Prof. 
Hansen  arrived,  and  stayed  with  me  to  July  4th. — From 
July  6th  to  loth  I  was  visiting  Dean  Peacock  at  Ely. — From 
July  23rd  to  29th  I  was  at  Playford,  where  for  the  first  time 
I  lodged  in  my  own  cottage.  I  had  bought  it  some  time 


AT   GREENWICH   OBSERVATORY — 1846   TO    1856.        183 

before,  and  my  sister  had  superintended  alterations  and  the 
addition  of  a  room.  I  was  much  pleased  thus  to  be  connected 
with  the  happy  scenes  of  my  youth. — From  Aug.  loth  to  Oct. 
nth  I  was  with  my  wife  and  her  sister  Elizabeth  Smith  on 
the  Continent.  We  stayed  for  some  time  at  Wiesbaden,  as 
my  nerves  were  shaken  by  the  work  on  the  Railway  Gauge 
Commission,  and  I  wanted  the  Wiesbaden  waters.  We 
visited  various  places  in  Germany,  and  made  a  lo-days' 
excursion  among  the  Swiss  Mountains.  At  Gotha  we 
lodged  with  Prof.  Hansen  for  three  days;  and  it  was  while 
staying  here  that  I  heard  from  Prof.  Encke  (on  Sept.  29th) 
that  Galle  had  discovered  the  expected  planet.  We  visited 
Gauss  at  Gottingen  and  Miss  Caroline  Herschel  at  Hannover. 
We  had  a  very  bad  passage  from  Hamburgh  to  London,  last- 
ing five  days :  a  crank-pin  broke  and  had  to  be  repaired  : 
after  four  days  our  sea-sickness  had  gone  off,  during  the 
gale — a  valuable  discovery  for  me,  as  I  never  afterwards 
feared  sea-sickness. — On  Dec.  22nd  I  attended  the  cele- 
bration of  the  3OOth  anniversary  of  Trinity  College." 


The  following  extracts  relating  to  the  engines  of  the 
"  Janus  "  are  taken  from  letters  to  his  wife  dated  from  Ports- 
mouth, Jan.  6th  and  /th,  1846 : 

As  soon  as  possible  we  repaired  to  the  Dock  Yard  and  presented 
ourselves  to  the  Admiral  Superintendant — Admiral  Hyde  Parker  (not 
Sir  Hyde  Parker).  Found  that  the  "  Janus  "  had  not  arrived  :  the 
Admiral  Superintendant  (who  does  not  spare  a  hard  word)  expressing 
himself  curiously  thereon.  But  he  had  got  the  proper  orders  from 
the  Admiralty  relating  to  me  :  so  he  immediately  sent  for  Mr  Taplin, 
the  Superintendant  of  machinery :  and  we  went  off  to  see  the  small 
engine  of  Lord  D — d's  construction  which  is  working  some  pumps  and 
other  machinery  in  the  yard.  It  was  kept  at  work  a  little  longer  than 
usual  for  us  to  see  it.  And  I  have  no  hesitation  in  saying  that  it  was 
working  extremely  well.  It  had  not  been  opened  in  any  way  for 
half  a  year,  and  not  for  repair  or  packing  for  a  much  longer  time.  .  .  . 
This  morning  we  went  to  the  Dock  Yard,  and  on  entering  the 
engine  house  there  was  Shirreff,  and  Lord  D — d  soon  appeared.  The 


1 84  GEORGE  BIDDELL  AIRY. 

" Janus"  had  come  to  anchor  at  Spithead  late  last  night,  and  had 
entered  the  harbour  this  morning.  Blowing  weather  on  Saturday 
night.  We  had  the  engine  pretty  well  pulled  to  pieces,  and  sat  con- 
templating her  a  long  time.,  Before-  this  Denison  had  come  to  us. 
We  then  went  on  board  the  "Janus  *  with  Shirreff  but  not  with  Lord 
D — d.  The  engines  were  still  hot,  and  so  they  were  turned  back- 
wards a  little  for  my  edification.  (This  was  convenient  because,  the 
vessel  being  moored  by  her  head,  she  could  thus  strain  backwards 
without  doing  mischief.)  The  vacuum  not  good.  Then,  after  a 
luncheon  on  board,  it  was  agreed  to  run  out  a  little  way.  But  the 
engines  absolutely  stuck  fast,  and  would  not  stir  a  bit.  This  I  con- 
sidered a  perfect  Godsend.  So  the  paddle-wheels  (at  my  desire) 
were  lashed  fast,  and  we  are  to  see  her  opened  to-morrow  morning. 

This  morning  (Jan.  yth)  we  all  went  off  to  the  "  Janus,"  where  we 
expected  to  find  the  end  of  the  cylinder  (where  we  believe  yesterday's 
block  to  have  taken  place)  withdrawn.  But  it  was  not  near  it.  After 
a  great  many  bolts  were  drawn,  it  was  discovered  that  one  bolt  could 
not  be  drawn,  and  in  order  to  get  room  for  working  at  it,  it  was 
necessary  to  take  off  the  end  of  the  other  cylinder.  And  such  a  job  ! 
Three  pulley  hooks  were  broken  in  my  sight,  and  I  believe  some  out 
of  my  sight.  However  this  auxiliary  end  was  at  last  got  off :  and  the 
people  began  to  act  on  the  refractory  bolt.  But  by  this  time  it  was 
getting  dark  and  the  men  were  leaving  the  dockyard,  so  I  left, 
arranging  that  what  they  could  do  in  preparation  for  me  might  be 
done  in  good  time  to-morrow  morning. 


1847 

"On  Nov.  1 3th  I  circulated  an  Address,  proposing  to 
discontinue  the  use  of  the  Zenith  Tube,  because  it  had  been 
found  by  a  long  course  of  comparative  trials  that  the  Zenith 
Tube  was  not  more  accurate  than  the  Mural  Circle.  The 
Address  stated  that  '  This  want  of  superior  efficiency  of  the 
Zenith  Tube  (which,  considered  in  reference  to  the  expecta- 
tions that  had  been  formed  of  its  accuracy,  must  be  estimated 
as  a  positive  failure)  is  probably  due  to  two  circumstances. 
One  is,  the  use  of  a  plumb-line ;  which  appears  to  be  affected 
with  various  ill-understood  causes  of  unsteadiness.  The 
other  is,  the  insuperable  difficulty  of  ventilating  the  room  in 


AT   GREENWICH   OBSERVATORY— 1846   TO    1856.        185 

which  the  instrument  is  mounted.' — On  December  2Oth  I 
circulated  an  Address,  proposing  a  Transit  Circle,  with 
telescope  of  8  inches  aperture.  The  Address  states  as 
follows :  '  The  clear  aperture  of  the  Object-Glass  of  our 
Transit  Instrument  is  very  nearly  5  inches,  that  of  our  Mural 
Circle  is  very  nearly  4  inches.' — I  had  been  requested  by  the 
Master-General  of  Ordnance  (I  think)  to  examine  Candidates 
for  a  Mastership  in  Woolwich  Academy,  and  I  was  employed 
on  it  in  February  and  March,  in  conjunction  with  Prof. 
Christie. — In  January  I  applied  to  Lord  Auckland  for 
money-assistance  to  make  an  astronomical  journey  on  the 
Continent,  but  he  refused. — On  Mar.  igth  Sir  James  South 
addressed  to  the  Admiralty  a  formal  complaint  against  me 
for  not  observing  with  the  astronomical  instruments :  on 
Mar.  3  ist  I  was  triumphantly  acquitted  by  the  Admiralty. — 
In  June  I  was  requested  by  the  Commissioners  of  Railways 
to  act  as  President  of  a  Commission  on  Iron  Bridges 
(suggested  by  the  fall  of  the  bridge  at  Chester).  Lord 
Auckland  objected  to  it,  and  I  was  not  sorry  to  be  spared 
the  trouble  of  it. — In  December  I  was  requested,  and  under- 
took to  prepare  the  Astronomical  part  of  the  Scientific 
Manual  for  Naval  Officers. — On  Sept.  24th  occurred  a  very 
remarkable  Magnetic  Storm,  to  which  there  had  been  nothing 
comparable  before.  Mr  Glaisher  had  it  observed  by  eye 
extremely  well,  and  I  printed  and  circulated  a  paper  con- 
cerning it. — Hansen,  stimulated  by  the  Lunar  Reductions, 
discovered  two  long  inequalities  in  the  motion  of  the  Moon, 
produced  by  the  action  of  Venus.  In  the  Report  to  the 
Visitors  this  matter  is  thus  referred  to :  'In  the  last  summer 
I  had  the  pleasure  of  visiting  Prof.  Hansen  at  Gotha,  and  I 
was  so  fortunate  as  to  exhibit  to  him  the  corrections  of  the 
elements  from  these  Reductions,  and  strongly  to  call  his 
attention  to  their  certainty,  the  peculiarity  of  their  fluctua- 
tions, and  the  necessity  of  seeking  for  some  physical  explana- 
tion. I  have  much  pleasure  in  indulging  in  the  thought,  that 
it  was  mainly  owing  to  this  representation  that  Prof.  Hansen 


1 86  GEORGE  BIDDELL  AIRY. 

undertook  that  quest,  which  has  terminated  in  the  discovery 
of  his  two  new  lunar  inequalities,  the  most  remarkable 
discovery,  I  think,  in  Physical  Astronomy.' — In  discussing 
points  relating  to  the  discovery  0f  Neptune,  I  made  an  un- 
fortunate blunder.  In  a  paper  hastily  sent  to  the  Athenaeum 
(Feb.  1 8th)  I  said  that  Arago's  conduct  had  been  indelicate. 
I  perceived  instantly  that  I  had  used  a  wrong  expression, 
and  by  the  very  next  post  I  sent  an  altered  expression. 
This  altered  expression  was  not  received  in  time,  and  the 
original  expression  was  printed,  to  my  great  sorrow.  I 
could  not  then  apologize.  But  at  what  appeared  to  be  the 
first  opportunity,  in  December,  I  did  apologize;  and  my 
apology  was  accepted.  But  I  think  that  Arago  was  never 
again  so  cordial  as  before. — On  July  4th  Hebe  was  discovered. 
After  this  Iris  and  Flora.  Now  commenced  that  train  of 
discoveries  which  has  added  more  than  100  planets  to  the 
Solar  System. — On  Oct.  8th  was  an  Annular  Eclipse  of  the 
Sun,  of  which  the  limit  of  annularity  passed  near  to  Green- 
wich. To  determine  the  exact  place,  I  equipped  obser- 
vatories at  Hayes,  Lewisham  South  End,  Lewisham  Village, 
Blackwall,  Stratford,  Walthamstow,  and  Chingford.  The 
weather  was  bad  and  no  observation  was  obtained. — In  the 
Royal  Astronomical  Society:  In  1846,  the  dispute  between 
the  partisans  of  Adams  and  Le  Verrier  was  so  violent  that  no 
medal  could  be  awarded  to  either.  In  1847  I  (with  other 
Fellows  of  the  Society)  promoted  a  special  Meeting  for  con- 
sidering such  a  modification  of  the  bye-laws  that  for  this 
occasion  only  it  might  be  permissible  to  give  two  medals. 
After  two  days'  stormy  discussion,  it  was  rejected. — In  the 
University  of  London :  At  a  meeting  in  July,  where  the 
religious  question  was  discussed,  it  was  proposed  to  receive 
some  testimonial  from  affiliated  bodies,  or  to  consider  that  or 
some  other  plan  for  introducing  religious  literature.  As  the 
propriety  of  this  was  doubtful,  there  was  a  general  feeling  for 
taking  legal  advice:  and  it  was  set  aside  solely  on  purpose  to 
raise  the  question  about  legal  consultation.  That  was  nega- 


AT   GREENWICH   OBSERVATORY — 1846   TO    1856.        1 87 

tived  by  vote  :  and  I  then  claimed  the  consideration  of  the 
question  which  we  had  put  aside  for  it.  By  the  influence  of 
H.  Warburton,  M.P.,  this  was  denied.  I  wrote  a  letter  to  be 
laid  before  the  Meeting  on  July  28th,  when  I  was  necessarily 
absent,  urging  my  claim :  my  letter  was  put  aside.  I 
determined  never  to  sit  with  Warburton  again  :  on  Aug.  2nd 
I  intimated  to  Lord  Burlington  my  wish  to  retire,  and  on 
Aug.  2Qth  he  transmitted  to  the  Home  Secretary  my  resig- 
nation. He  (Lord  Burlington)  fully  expressed  his  opinion 
that  my  claim  ought  to  have  been  allowed. — On  June  Qth,  on 
the  occasion  of  Prince  Albert's  state  visit  to  Cambridge, 
knighthood  was  offered  to  me  through  his  Secretary,  Prof. 
Sedgwick,  but  I  declined  it. — In  September,  the  Russian 
Order  of  St  Stanislas  was  offered  to  me,  Mr  De  Berg,  the 
Secretary  of  Embassy,  coming  to  Greenwich  personally  to 
announce  it:  but  I  was  compelled  by  our  Government 
Rules  to  decline  it. — I  invited  Le  Verrier  to  England,  and 
escorted  him  to  the  Meeting  of  the  British  Association  at 
Oxford  in  June. — As  regards  the  Westminster  Clock  on  the 
Parliamentary  Building:  in  May  I  examined  and  re- 
ported on  Dent's  and  Whitehurst's  clock  factories.  Vulliamy 
was  excessively  angry  with  me.  On  May  3ist  a  great 
Parliamentary  Paper  was  prepared  in  return  to  an  Order  of 
the  House  of  Lords  for  correspondence  relating  to  the  Clock. 
— With  respect  to  the  Saw  Mills  for  Ship  Timber:  work 
was  going  on  under  the  direction  of  Sylvester  to  Mar.  i8th. 
It  was,  I  believe,  at  that  time,  that  the  fire  occurred  in 
Chatham  Dock  Yard  which  burnt  the  whole  of  the  saw- 
machinery.  I  was  tired  of  my  machinery :  and,  from  the 
extending  use  of  iron  ships,  the  probable  value  of  it  was 
much  diminished ;  and  I  made  no  effort  to  restore  it." 

Of  private  history  :  "  In  February  I  went  to  Derby  to  see 
Whitehurst's  clock  factory ;  and  went  on  with  my  wife  to 
Brampton  near  Chesterfield,  where  her  mother  was  living. — 
From  Apr.  1st  to  5th  I  was  at  Playford. — On  Holy  Thursday, 
I  walked  the  Parish  Bounds  (of  Greenwich)  with  the  Parish 


1 88  GEORGE   BIDDELL   AIRY. 

officers  and  others.  From  Apr.  igth  to  24th  I  was  at  Birming- 
ham (on  a  visit  to  Guest,  my  former  pupil,  and  afterwards 
Master  of  Caius  College)  and  its  neighbourhood,  with  George 
Arthur  Biddell. — From  June  23^  to  28th  I  was  at  Oxford 
and  Malvern  :  my  sister  was  at  Malvern,  for  water-cure :  the 
meeting  of  the  British  Association  was  at  Oxford  and  I 
escorted  Le  Verrier  thither. — July  28th  to  3Oth  I  was  at 
Brampton. — From  August  loth  to  September  i8th  I  was 
engaged  on  an  expedition  to  St  Petersburg,  chiefly  with  the 
object  of  inspecting  the  Pulkowa  Observatory.  I  went  by 
Hamburg  to  Altona,  where  I  met  Struve,  and  started  with 
him  in  an  open  waggon  for  Liibeck,  where  we  arrived  on 
Aug.  1 4th.  We  proceeded  by  steamer  to  Cronstadt  and 
Petersburg,  and  so  to  Pulkowa,  where  I  lodged  with  O. 
Struve.  I  was  -here  engaged  till  Sept.  4th,  in  the  Obser- 
vatory, in  expeditions  in  the  neighbourhood  and  at  St 
Petersburg,  and  at  dinner-parties,  &c.  I  met  Count 
Colloredo,  Count  Ouvaroff,  Count  StroganofF,  Lord  Bloom- 
field  (British  Ambassador),  and  others.  On  Sept.  4th  I  went 
in  a  small  steamer  to  Cronstadt,  and  then  in  the  Vladimir 
to  Swinemiinde:  we  were  then  towed  in  a  passage  boat  to 
Stettin,  and  I  proceeded  by  railway  to  Berlin.  On  Sept. 
9th  I  found  Galle  and  saw  the  Observatory.  On  Sept.  loth 
I  went  to  Potzdam  and  saw  Humboldt.  On  the  I2th  I  went 
to  Hamburg  and  lodged  with  Schumacher :  I  here  visited 
Repsold  and  Rumker.  On  Sept.  I4th  I  embarked  in  the 
John  Bull  for  London,  and  arrived  there  on  the  evening  of 
the  1 8th:  on  the  i6th  it  was  blowing  'a  whole  gale,' 
reported  to  be  the  heaviest  gale  known  for  so  many  hours ; 
4  bullocks  and  24  sheep  were  thrown  overboard. — From  Dec. 
3rd  to  8th  I  was  at  Cambridge,  and  from  the  22nd  to  3ist  at 
Playford." 


Here  is  a  letter  to  his  wife  written  from  Birmingham, 
containing  a  note  of  the  progress  of  the  ironwork  for  the 
Menai  Bridge  : 


AT   GREENWICH   OBSERVATORY— 1846   TO    1856.        189 


EDGBASTON,  BIRMINGHAM, 
1847,  Apr.  22. 

Yesterday  morning  we  started  between  10  and  n  for  Stourbridge, 
first  to  see  some  clay  which  is  celebrated  all  over  the  world  as  the 
only  clay  which  is  fit  to  make  pots  for  melting  glass,  &c.  You  know 
that  in  all  these  fiery  regions,  fire-clay  is  a  thing  of  very  great  im- 
portance, as  no  furnace  will  stand  if  made  of  any  ordinary  bricks 
(and  even  with  the  fire-clay,  the  small  furnaces  are  examined  every 
week),  but  this  Stourbridge  clay  is  as  superior  to  fire-clay  as  fire-clay 
is  to  common  brick-earth.  Then  we  went  to  Fosters'  puddling  and 
rolling  works  near  Stourbridge.  These  are  on  a  very  large  scale :  of 
course  much  that  we  saw  was  a  repetition  of  what  we  had  seen  before, 
but  there  were  slitting  mills,  machines  for  rolling  the  puddled  blooms 
instead  of  hammering  them,  &c.,  and  we  had  the  satisfaction  of 
handling  the  puddling  irons  ourselves.  Then  we  went  to  another 
work  of  the  Fosters  not  far  from  Dudley,  where  part  of  the  work  of 
the  Tube  Bridge  for  the  Menai  is  going  on.  The  Fosters  are,  I 
believe,  the  largest  iron  masters  in  the  country,  and  the  two  principal 
partners,  the  elder  Mr  Foster  and  his  Nephew,  accompanied  us  in 
all  our  inspections  and  steppings  from  one  set  of  works  to  another. 
The  length  of  Tube  Bridge  which  they  have  in  hand  here  is  only 
1 20  feet,  about  \  of  the  whole  length:  and  at  present  they  are  only 
busy  on  the  bottom  part  of  it :  but  it  is  a  prodigious  thing.  I  shall 
be  anxious  about  it.  Then  we  went  to  other  works  of  the  Fosters' 
at  King's  Wynford,  where  they  have  blast  furnaces:  and  here  after 
seeing  all  other  usual  things  we  saw  the  furnaces  tapped.  In  this 
district  the  Fosters  work  the  lo-yard  coal  in  a  way  different  from 
any  body  else:  they  work  out  the  upper  half  of  its  thickness  and 
then  leave  the  ground  to  fall  in:  after  a  year  or  two  this  ground 
becomes  so  hard  as  to  make  a  good  safe  roof,  and  then  they  work 
away  the  other  half:  thus  they  avoid  much  of  the  danger  and  diffi- 
culty of  working  the  thick  bed  all  at  once.  The  ventilation  of  these 
mines  scarcely  ever  requires  fires,  and  then  only  what  they  call 
"lamps,"  those  little  fire-places  which  are  used  for  giving  light  at 
night.  (In  the  Northumberland  and  Durham  pits,  they  constantly 
have  immense  roaring  fires  to  make  a  draught.)  Then  we  came 
home  through  Dudley. 


190  GEORGE   BIDDELL  AIRY. 

During  his  stay  in  Russia,  there  was  a  great  desire 
manifested  by  the  astronomers  and  scientific  men  of  Russia 
that  he  should  be  presented  to  the  Emperor.  This  would  no 
doubt  have  taken  place  had  not  tj*e  movements  of  the  Court 
and  his  own  want  of  time  prevented  it.  The  following 
letter  to  the  British  Ambassador,  Lord  Bloomfield,  relates  to 
this  matter : 

PULKOWA, 
1847,  August  2$th. 
Wednesday  evening. 
MY  LORD, 

I  had  the  honour  yesterday  to  receive  your  Lordship's 
note  of  Sunday  last,  which  by  some  irregularity  in  the  communi- 
cations with  this  place  reached  me,  I  believe,  later  than  it  ought. 
From  this  circumstance,  and  also  from  my  being  made  acquainted 
only  this  afternoon  with  some  official  arrangements,  I  am  compelled 
to  trouble  you  at  a  time  which  I  fear  is  less  convenient  than  I  could 
have  desired. 

The  object  of  my  present  communication  is,  to  ask  whether  (if 
the  movements  of  the  Court  permit  it)  it  would  be  agreeable  to  your 
Lordship  to  present  me  to  the  Emperor.  In  explanation  of  this 
enquiry,  I  beg  leave  to  state  that  this  is  an  honour  to  which, 
personally,  I  could  not  think  of  aspiring.  My  presence  however  at 
Pulkowa  at  this  time  is  in  an  official  character.  As  Astronomer 
Royal  of  England,  I  have  thought  it  my  duty  to  make  myself 
perfectly  acquainted  with  the  Observatory  of  Pulkowa,  and  this  is 
the  sole  object  of  my  journey  to  Russia.  It  is  understood  that  the 
Emperor  takes  great  interest  in  the  reputation  of  the  Observatory, 
and  I  am  confident  that  the  remarks  upon  it  which  I  am  able  to 
make  would  be  agreeable  to  him. 

I  place  these  reasons  before  you,  awaiting  entirely  Your  Lord- 
ship's decision  on  the  propriety  of  the  step  to  which  I  have  alluded. 
I  am  to  leave  St  Petersburg  on  Saturday  the  4th  of  Septeoiber. 

I  have  the  honor  to  be 

My  Lord, 
Your  Lordship's  very  faithful  servant, 

G.    B.    AIRY. 

Lord  Bloomfield,  6^.,  6°<r. 


AT   GREENWICH   OBSERVATORY  —  1846   TO    1856.        191 

It  was  probably  in  acknowledgment  of  this  letter  that  in 
due  time  he  received  the  following  letter  with  the  offer  of  the 
Russian  Order  of  St  Stanislas  : 

MONSIEUR  L'ASTRONOME  ROYAL, 

Sa  Majeste  1'Empereur  en  appre'ciant  les  travaux  assidus 
qui  vous  ont  donn£  une  place  distinguee  au  rang  des  plus  illustres 
Astronomes  de  1'Europe,  et  la  cooperation  bienveillante,  que  vous 
n'avez  cesse  de  temoigner  aux  Astronomes  Russes  dans  les  expe- 
ditions, dont  ils  etaient  charge's,  et  en  dernier  lieu  par  votre  visite  a 
1'Observatoire  central  de  Poulkova,  a  daigne  sur  mon  rapport,  vous 
nommer  Chevalier  de  la  seconde  classe  de  POrdre  Imperial  et 
Royal  de  St  Stanislas.  Je  ne  manquerai  pas  de  vous  faire  parvenir 
par  1'entremise  de  Lord  Bloomfield  les  insignes  et  la  patente  de 
1'ordre. 

Veuillez  en  attendant,  Monsieur,  recevoir  mes  sinceres  felici- 
tations et  1'assurance  de  ma  parfaite  consideration. 

Le  Ministre  de  1'instruction  publique, 

CTE  OUVAROFF. 
ST  PETERSBOURG, 
24  A  out 


a  Mr  G.  B.  Airy,  Esq., 
Astronome  Royal  de  S.  M.  Britannique  a 

Greenwich. 


Airy  provisionally  accepted  the  Order,  but  wrote  at  once 
to  Lord  John  Russell  the  following  letter  of  enquiry  : 

ROYAL  OBSERVATORY,  GREENWICH, 

1847,  Oct.  15. 
MY  LORD, 

In  respect  of  the  office  of  Astronomer  Royal,  I  refer 
to  the  first  Lord  of  the  Treasury  as  Official  Patron.  In  virtue  of  this 
relation  I  have  the  honour  to  lay  before  your  Lordship  the  following 
statement,  and  to  solicit  your  instructions  thereon. 

For  conducting  with  efficiency  and  with  credit  to  the  nation  the 
institution  which  is  entrusted  to  me,  I  have  judged  it  proper  to 
cultivate  intimate  relations  with  the  principal  Observatories  of 


IQ2  GEORGE   BIDDELL  ATRY. 

Europe,  and  in  particular  with  the  great  Observatory  founded  by  the 
Emperor  of  Russia  at  Pulkowa  near  St  Petersburg.  I  have  several 
times  received  Mr  Struve,  the  Director  of  that  Observatory,  at 
Greenwich:  and  in  the  past  summer  I  made  a  journey  to  St 
Petersburg  for  the  purpose  of  seeing  the  Observatory  of  Pulkowa. 

Since  my  return  from  Russia,  I  have  received  a  communication 
from  Count  Ouvaroff,  Minister  of  Public  Instruction  in  the  Russian 
Empire,  informing  me  that  the  Emperor  of  Russia  desires  to  confer 
on  me  the  decoration  of  Knight  Commander  in  the  second  rank  of 
the  Order  of  St  Stanislas. 

And  I  have  the  honour  now  to  enquire  of  your  Lordship  whether 
it  is  permitted  to  me  to  accept  from  the  Emperor  of  Russia  this 
decoration. 

I  have  the  honour  to  be, 

My  Lord, 
Your  Lordship's  very  obedient  servant, 

G.    B.    AIRY. 
The  Rt  Honble  Lord  John  Russell, 

&c.         &c.         &*c. 
First  Lord  of  the  Treasury. 


The  answer  was  as  follows : 

DOWNING  STREET, 
October  19,  1847. 
SIR, 

I  am  desired  by  Lord  John  Russell  to  acknowledge  the 
receipt  of  your  letter,  of  the  i4th  inst.  and  to  transmit  to  you  the 
enclosed  paper  respecting  Foreign  Orders  by  which  you  will  per- 
ceive that  it  would  be  contrary  to  the  regulations  to  grant  you  the 
permission  you  desire. 

I  am,  Sir, 
Your  obedient  servant, 

C.  A.  GREY. 
G.  B.  Airy,  Esq. 


The   passage   in   the   Regulations   referred   to   above   is 
quoted  in  the  following  letter  to  Count  Ouvaroff: 


AT   GREENWICH   OBSERVATORY — 1846   TO    1856.       193 


ROYAL  OBSERVATORY,  GREENWICH, 

1847,  Oct.  22. 
SIR, 

Referring  to  your  Excellency's  letter  of  the  — ^ \JT  > 

to  my  answer  of  the  25th  September,  in  which  I  expressed  my  sense 
of  the  high  honor  conferred  on  me  by  His  Majesty  the  Emperor  of 
Russia  in  offering  me,  through  your  Excellency,  the  Order  of  St 
Stanislas,  and  my  pride  in  accepting  it: — I  beg  leave  further  to 
acquaint  you  that  I  have  thought  it  necessary  to  make  enquiry  of 
Lord  John  Russell,  First  Lord  of  Her  Majesty's  Treasury,  as  to  my 
competency  to  accept  this  decoration  from  His  Majesty  the  Emperor 
of  Russia:  and  that  his  Lordship  in  reply  has  referred  me  to  the 
following  Regulation  of  the  British  Court; 

"5th.  That  no  Subject  of  Her  Majesty  could  be  allowed  to 
accept  the  Insignia  of  a  Foreign  Order  from  any  Sovereign  of  a 
Foreign  State,  except  they  shall  be  so  conferred  in  consequence  of 
active  and  distinguished  services  before  the  Enemy,  either  at  Sea,  or 
in  the  Field ;  or  unless  he  shall  have  been  actually  employed  in  the 
Service  of  the  Foreign  Sovereign." 

In  consequence  of  the  stringency  of  this  Regulation,  it  is  my 
duty  now  to  state  to  your  Excellency  that  I  am  unable  to  accept  the 
decoration  which  His  Majesty  the  Emperor  of  Russia  was  pleased, 
through  your  Excellency,  to  offer  to  me. 

I  beg  leave  to  repeat  the  expression  of  my  profound  reverence 
to  His  Majesty  and  of  my  deep  sense  of  the  honor  which  he  has 
done  me. 

I  have  the  honor  to  be, 

Sir, 
Your  Excellency's  very  faithful 

and  obedient  servant, 

G.    B.   AIRY. 
To  His  Excellency 
Count  Ouvaroff) 


In  the  course  of  the  following  year  a  very  handsome  gold 
medal,  specially  struck,  was  transmitted  by  Count  Ouvaroff 
on  the  part  of  the  Emperor  of  Russia,  to  Mr  Airy. 

A.  B.  13 


194  GEORGE    BIDDELL   AIRY. 


1848 

"  In  April  I  received  Authority  to  purchase  of  Simms  an 
8-inch  object-glass  for  the  new  Transit  Circle  for  £300.  The 
glass  was  tested  and  found  satisfactory.  While  at  Playford 
in  January  I  drew  the  first  plans  of  the  Transit  Circle  :  and 
C.  May  sketched  some  parts.  Definite  plans  were  soon  sent  to 
Ransomes  and  May,  and  to  Simms  in  March.  The  instru- 
ment and  the  building  were  proceeded  with  during  the  year. 
The  New  Transit  Circle  was  to  be  erected  in  the  Circle 
Room,  and  considerable  arrangement  was  necessary  for 
continuing  the  Circle  Observations  with  the  existing  instru- 
ments, whilst  the  new  instrument  was  under  erection.  When 
the  new  Transit  is  completely  mounted,  the  old  Transit 
Instrument  may  be  removed,  and  the  Transit  Room  will 
be  free  for  any  other  purpose.  I  propose  to  take  it  as 
Private  Room  for  the  Astronomer  Royal. — On  May  I2th  I 
made  my  first  proposal  of  the  Reflex  Zenith  Tube.  The 
principle  of  it  is  as  follows :  Let  the  micrometer  be  placed 
close  to  the  object-glass,  the  frame  of  the  micrometer  being 
firmly  connected  with  the  object-glass  cell,  and  a  reflecting 
eye-piece  being  used  with  no  material  tube  passing  over  the 
object-glass :  and  let  a  basin  of  quicksilver  be  placed  below 
the  object-glass,  but  in  no  mechanical  connection  with  it,  at  a 
distance  equal  to  half  the  focal  length  of  the  object-glass. 
Such  an  instrument  would  at  least  be  free  from  all  uncertain- 
ties of  twist  of  plumb-line,  viscosity  of  water,  attachment  of 
upper  plumb-line  microscope,  attachment  of  lower  plumb-line 
microscope,  and  the  observations  connected  with  them :  and 
might  be  expected,  as  a  result  of  this  extreme  simplicity,  to 
give  accurate  results. — A  considerable  error  was  discovered 
in  the  graduation  of  Troughton's  Circle,  amounting  in  one 
part  to  six  seconds,  which  is  referred  to  as  follows :  '  This 
instance  has  strongly  confirmed  me  in  an  opinion  which  I 
have  long  held — that  no  independent  division  is  comparable 


AT   GREENWICH   OBSERVATORY — 1846   TO    1856.        195 

in  general  accuracy  to  engine-division,  where  the  fundamental 
divisions  of  the  engine  have  been  made  by  Troughton's 
method,  and  where  in  any  case  the  determination  by  the 
astronomer  of  errors  of  a  few  divisions  will  suffice,  in  conse- 
quence of  the  uniformity  of  law  of  error,  to  give  the  errors  of 
the  intermediate  divisions.' — The  method  of  observing  with 
the  Altazimuth  is  carefully  described,  and  the  effect  of  it,  in 
increasing  the  number  of  observations  of  the  Moon,  is  thus 
given  for  the  thirteen  lunations  between  1847,  May  15,  and 
1848,  May  30.  'Number  of  days  of  complete  observations 
with  the  Meridional  Instruments,  in  ;  number  of  days  of 
complete  observations  with  Altitude  and  Azimuth  Instru- 
ment, 203.  The  results  of  the  observations  appear  very  good  ; 
perhaps  a  little,  and  but  a  little,  inferior  to  those  of  the 
Meridional  Instruments.  I  consider  that  the  object  for 
which  this  instrument  was  erected  is  successfully  attained.' — 
Being  satisfied  with  the  general  efficiency  of  the  system 
arranged  by  Mr  Brooke  for  our  photographic  records  (of 
magnetical  observations)  I  wrote  to  the  Admiralty  in  his 
favour,  and  on  Aug.  25th  the  Admiralty  ordered  the  pay- 
ment of  ^500  to  him.  A  Committee  of  the  Royal  Society 
also  recommended  a  reward  of  £250  to  Mr  Ronalds,  which  I 
believe  was  paid  to  him. — On  May  1st  the  last  revise  of  the 
Lunar  Reductions  was  passed,  and  on  May  5th,  500  copies 
were  sent  for  binding. — In  this  year  Schumacher  and  I 
refused  a  medal  to  Miss  Mitchell  for  a  Comet  discovered, 
because  the  rules  of  correspondence  had  not  been  strictly 
followed  :  the  King  of  Denmark  gave  one  by  special  favour. — 
In  this  year  occurred  the  discovery  of  Saturn's  8th  Satellite 
by  Mr  Lassell :  upon  which  I  have  various  correspondence. — 
On  the  1 8th  of  December  the  degree  of  LL.D.  was  conferred 
upon  me  by  the  University  of  Edinburgh. — The  Ipswich 
Lectures:  A  wish  had  been  expressed  that  I  would  give  a 
series  of  Astronomical  Lectures  to  the  people  of  Ipswich.  I 
therefore  arranged  with  great  care  the  necessary  apparatus, 
and  lectured  six  evenings  in  a  room  (I  forget  its  name — it 

13—2 


196  GEORGE  BIDDELL  AIRY. 

might  be  Temperance  Hall — high  above  St  Matthew's 
Street),  from  Mar.  1 3th  to  the  end  of  the  week.  A  short- 
hand writer  took  them  down  :  and  these  formed  the  '  Ipswich 
Lectures,'  which  were  afterwards  published  by  the  Ipswich 
Museum  (for  whose  benefit  the  lectures  were  given)  and  by 
myself,  in  several  editions,  and  afterwards  by  Messrs  Macmillan 
in  repeated  editions  under  the  title  of  '  Airy's  Popular  As- 
tronomy.'— It  had  been  found  necessary  to  include  under 
one  body  all  the  unconnected  Commissions  of  Sewers  for 
the  Metropolis,  and  Lord  Morpeth  requested  me  to  be  a 
member.  Its  operations  began  on  Oct.  28th.  In  constitu- 
tion it  was  the  most  foolish  that  I  ever  knew :  consisting  of, 
I  think,  some  200  persons,  who  could  not  possibly  attend  to 
it.  It  came  to  an  end  in  the  next  year." 

Of  private  history  :  "  I  was  at  Playford  from  Jan.  1st  to 
nth,  and  again  from  Jan.  i/th  to  25th:  also  at  Playford  from 
June  2  ist  to  July  I2th. — From  Aug.  23rd  to  Sept.  I2th  I  was 
in  Ireland  on  a  visit  to  Lord  Rosse  at  Parsonstown,  chiefly 
engaged  on  trials  of  his  large  telescope.  I  returned  by  Liver- 
pool, where  I  inspected  the  Liverpool  Equatoreal  and  Clock- 
work, and  examined  Mr  Lassell's  telescopes  and  grinding 
apparatus. — From  Dec.  6th  to  2Oth  I  was  at  Edinburgh  with 
my  wife,  on  a  visit  to  Prof.  J.  D.  Forbes.  We  made  various 
excursions,  and  I  attended  lectures  by  Prof.  Wilson  and  Sir 
W.  Hamilton  :  on  the  i8th  I  gave  a  lecture  in  Prof.  Forbes's 
room.  I  received  the  Honorary  Degree  of  LL.D.,  and  made 
a  statement  on  the  Telescopes  of  Lord  Rosse  and  Mr  Lassell 
to  the  Royal  Society  of  Edinburgh.  Returned  to  Greenwich 
by  Brampton." 


Here  is  a  reminiscence  of  the  "  Ipswich  Lectures,"  in  a 
letter  to  his  wife,  dated  Playford,  1848  Mar.  14,  "At  the 
proper  time  I  went  to  the  hall :  found  a  chairman  installed 
(Mr  Western) :  was  presented  to  him,  and  by  him  presented 
to  the  audience  :  made  my  bow  and  commenced.  The  room 


AT   GREENWICH   OBSERVATORY — 1846   TO    1856,        197 

was  quite  full :  I  have  rarely  seen  such  a  sea  of  faces  ;  about 
700  I  believe.  Everything  went  off  extremely  well,  except 
that  the  rollers  of  the  moving  piece  of  sky  would  squeak  : 
but  people  did  not  mind  it :  and  when  first  a  star  passed  the 
meridian,  then  Jupiter,  then  some  stars,  and  then  Saturn,  he 
was  much  applauded.  Before  beginning  I  gave  notice  that  I 
should  wait  to  answer  questions  :  and  as  soon  as  the  lecture 
was  finished  the  Chairman  repeated  this  and  begged  people 
to  ask.  So  several  people  did  ask  very  pertinent  questions 
(from  the  benches)  shewing  that  they  had  attended  well. 
Others  came  up  and  asked  questions." 


The  following  extracts  are  from  letters  written  to  his 
wife  while  on  his  visit  to  Lord  Rosse  at  Parsonstown  in 
Ireland.  On  the  way  he  stopped  at  Bangor  and  looked  at 
the  Tubular  Bridge  Works,  which  are  thus  referred  to: 
"  Stopped  at  Bangor,  settled  pro  tern,  at  the  Castle,  and  then 
walked  past  the  Suspension  Bridge  towards  the  Tube  Works, 
which  are  about  ij  mile  south-west  of  the  Suspension  Bridge. 
The  way  was  by  a  path  through  fields  near  the  water  side : 
and  from  one  or  two  points  in  this,  the  appearance  of  the 
Suspension  Bridge  was  most  majestic.  The  Tube  Bridge 
consists  of  four  spans,  two  over  water  and  two  over  sloping 
land.  The  parts  for  the  double  tube  over  the  water  spans 
(four  lengths  of  tube)  are  building  on  a  platform  as  at  Con- 
way,  to  be  floated  by  barges  as  there :  the  parts  over  the 
sloping  banks  are  to  be  built  in  their  place,  on  an  immense 
scaffolding.  I  suspect  that,  in  regard  to  these  parts,  Stephen- 
son  is  sacrificing  a  great  deal  of  money  to  uniformity  of  plan  : 
and  that  it  would  have  been  much  cheaper  to  build  out  stone 

arches  to  the  piers  touching  the  water The  Tube  Works 

are  evidently  the  grand  promenade  of  the  idlers  about  Bangor  : 
I  saw  many  scores  of  ladies  and  gentlemen  walking  that  way 
with  their  baskets  of  provision,  evidently  going  to  gipsy  in 
the  fields  close  by." 


198  GEORGE   BIDDELL  AIRY. 


THE  CASTLE,  PARSONSTOWN, 

1848,  Aug.  29. 

After  tea  it  was  voted  that  the  night  was  likely  to  be  fine,  so  we 
all  turned  out.  The  night  was  uncertain  :  sometimes  entirely  clouded, 
sometimes  partially,  but  objects  were  pretty  well  seen  when  the  sky 
was  clear  :  the  latter  part  was  much  steadier.  From  the  interruption 
by  clouds,  the  slowness  of  finding  with  and  managing  a  large  instru- 
ment (especially  as  their  finding  apparatus  is  not  perfectly  arranged) 
and  the  desire  of  looking  well  at  an  object  when  we  had  got  it,  we 
did  not  look  at  many  objects.  The  principal  were,  Saturn  and  the 
Annular  Nebula  of  Lyra  with  the  3-feet ;  Saturn,  a  remarkable  cluster 
of  stars,  and  a  remarkable  planetary  nebula,  with  the  6-feet.  With 
the  large  telescope,  the  evidence  of  the  quantity  of  light  is  prodigious. 
And  the  light  of  an  object  is  seen  in  the  field  without  any  colour  or 
any  spreading  of  stray  light :  and  it  is  easy  to  see  that  the  vision 
with  a  reflecting  telescope  may  be  much  more  perfect  than  with 
a  refractor.  With  these  large  apertures,  the  rings  round  the  stars 
are  insensible.  The  planetary  nebula  looked  a  mass  of  living  and 
intensely  brilliant  light :  this  is  an  object  which  I  do  not  suppose 
can  be  seen  at  all  in  our  ordinary  telescopes.  The  definition  of  the 
stars  near  the  zenith  is  extremely  good  :  with  a  high  power  (as  800) 
they  are  points  or  very  nearly  so — indeed  I  believe  quite  so — so  that 
it  is  clear  that  the  whole  light  from  the  great  6-feet  mirror  is  collected 
into  a  space  not  bigger  than  the  point  of  a  needle.  But  in  other 
positions  of  the  telescope  the  definition  is  not  good  :  and  we  must 
look  to-day  to  see  what  is  the  cause  of  this  fault.  It  is  not  a  fault  in 
the  telescope,  properly  so-called,  but  it  is  either  a  tilt  of  the  mirror, 
or  an  edge-pressure  upon  the  mirror  when  the  telescope  points  lower 
down  which  distorts  its  figure,  or  something  of  that  kind.  So  I  could 
not  see  Saturn  at  all  well,  for  which  I  was  sorry,  as  I  could  so  well 
have  compared  his  appearance  with  what  I  have  seen  before.  I  shall 
be  very  much  pleased  if  we  can  make  out  what  is  the  fault  of  ad- 
justment, and  so  correct  it  as  to  get  good  images  everywhere.  It  is 
evident  that  the  figuring  of  the  mirror,  the  polishing,  and  the  general 
arrangement,  are  perfectly  managed. 


AT   GREENWICH   OBSERVATORY — 1846   TO    1856.        199 


THE  CASTLE,  PARSONSTOWN, 

1848,  Aug.  30. 

Yesterday  we  were  employed  entirely  about  the  Great  Telescope, 
beginning  rather  late.  The  principal  objects  had  relation  to  the 
fault  of  definition  when  the  telescope  is  pointed  low  (which  I  had 
remarked  on  the  preceding  night),  and  were,  to  make  ourselves 
acquainted  with  the  mechanism  of  the  mirror's  mounting  generally, 
and  to  measure  in  various  ways  whether  the  mirror  actually  does  shift 
its  place  when  the  telescope  is  set  to  different  angles  of  elevation. 
For  the  latter  we  found  that  the  mirror  actually  does  tilt  \  of  an  inch 
when  the  tube  points  low.  This  of  itself  will  not  account  for  the 
fault  but  it  indicates  that  the  lower  part  is  held  fast  in  a  way  that  may 
cause  a  strain  which  would  produce  the  fault.  These  operations  and 
reasonings  took  a  good  deal  of  time.  Lord  Rosse  is  disposed  to 
make  an  alteration  in  the  mounting  for  the  purpose  of  correcting 
this  possible  strain. 


THE  CASTLE,  PARSONSTOWN, 

1848,  Aug.  31. 

The  weather  here  is  still  vexatious  :  but  not  absolutely  repulsive. 
Yesterday  morning  Lord  Rosse  arranged  a  new  method  of  suspend- 
ing the  great  mirror,  so  as  to  take  its  edgewise  pressure  in  a  manner 
that  allowed  the  springy  supports  of  its  flat  back  to  act.  This  em- 
ployed his  workmen  all  day,  so  that  the  proposed  finish  of  polishing 
the  new  mirror  could  not  go  on.  I  took  one  Camera  Lucida  sketch 
of  the  instrument  in  the  morning,  dodging  the  heavy  showers  as  well 
as  I  could;  then,  as  the  afternoon  was  extremely  fine,  I  took 
another,  with  my  head  almost  roasted  by  the  sun.  This  last  view  is 
extremely  pretty  and  characteristic,  embracing  parts  of  the  mounting 
not  shewn  well  in  the  others,  and  also  shewing  the  Castle,  the 
Observatory,  and  the  3 -feet  telescope.  The  night  promised  exceed- 
ingly well :  but  when  we  got  actually  to  the  telescope  it  began  to 
cloud  and  at  length  became  hopeless.  However  I  saw  that  the  fault 
which  I  had  remarked  on  the  two  preceding  nights  was  gone.  There 
is  now  a  slight  exhibition  of  another  fault  to  a  much  smaller  extent. 
We  shall  probably  be  looking  at  the  telescope  to-day  in  reference 
to  it. 


200  GEORGE   BIDDELL  AIRY. 


THE  CASTLE,  PARSONSTOWN, 

1848,  Sept.  i. 

A 

Yesterday  we  made  some  alterations  in  the  mounting  of  the  great 
mirror.  We  found  that  sundry  levers  were  loose  which  ought  to  be 
firm,  and  we  conjectured  with  great  probability  the  cause  of  this,  for 
correction  of  which  a  change  in  other  parts  was  necessary.  The 
mirror  was  then  found  to  preserve  its  position  much  more  fixedly 
than  before.  ...  .  At  night,  upon  trying  the  telescope,  we  found  it 
very  faulty  for  stars  near  the  zenith,  where  it  had  been  free  from  fault 
before.  The  screws  which  we  had  driven  hard  were  then  loosened, 
and  immediately  it  was  made  very  good.  Then  we  tried  with  some 
lower  objects,  and  it  was  good,  almost  equally  good,  there.  For 
Saturn  it  was  very  greatly  superior  to  what  it  had  been  before.  Still 
it  is  not  satisfactory  to  us,  and  at  this  time  a  strong  chain  is  in  pre- 
paration, to  support  the  mirror  edgeways  instead  of  the  posts  that 
there  were  at  first  or  the  iron  hoop  which  we  had  on  it  yesterday. 

Nobody  would  have  conceived  that  an  edgewise  gripe  of  such  a 
mass  of  metal  could  derange  its  form  in  this  way. 

Last  night  was  the  finest  night  we  have  had  as  regards  clouds, 
though  perhaps  not  the  best  for  definition  of  objects. 


THE  CASTLE,  PARSONSTOWN, 

1848,  Sept.  2. 

I  cannot  learn  that  the  fault  in  the  mirror  had  been  noticed 
before,  but  I  fancy  that  the  observations  had  been  very  much  con- 
fined to  the  Zenith  and  its  neighbourhood. 


1849 

"  In  July  the  new  constant-service  water-pipes  to  the 
Observatory  were  laid  from  Blackheath.  Before  this  time 
the  supply  of  water  to  the  Observatory  had  been  made  by  a 
pipe  leading  up  from  the  lower  part  of  the  Park,  and  was  not 
constant. — In  May  the  new  staircase  from  my  dwelling-house 
to  the  Octagon  Room  was  commenced. — In  the  Report  to 
the  Visitors  there  is  a  curious  account  of  Mr  Breen's  (one  of 


AT   GREENWICH   OBSERVATORY — 1846   TO    1856.       2OI 

the  Assistants)  personal  equation,  which  was  found  to  be 
different  in  quantity  for  observations  of  the  Moon  and  obser- 
vations of  the  Stars. — The  most  important  set  of  observations 
(of  planets)  was  a  series  of  measures  of  Saturn  in  four  direc- 
tions, at  the  time  when  his  ring  had  disappeared.  They 
appear  completely  to  negative  the  idea  that  Saturn's  form 
differs  sensibly  from  an  ellipsoid. — Among  the  General 
Remarks  of  the  Report  the  following  appears :  '  Another 
change  (in  prospect)  will  depend  on  the  use  of  galvanism ; 
and  as  a  probable  instance  of  the  application  of  this  agent,  I 
may  mention  that,  although  no  positive  step  has  hitherto 
been  taken,  I  fully  expect  in  no  long  time  to  make  the  going 
of  all  the  clocks  in  the  Observatory  depend  on  one  original 
regulator.  The  same  means  will  probably  be  employed  to 
increase  the  general  utility  of  the  Observatory,  by  the  exten- 
sive dissemination  throughout  the  kingdom  of  accurate  time- 
signals,  moved  by  an  original  clock  at  the  Royal  Observa- 
tory; and  I  have  already  entered  into  correspondence  with 
the  authorities  of  the  South  Eastern  Railway  (whose  line  of 
galvanic  communication  will  shortly  pass  within  nine  furlongs 
of  the  Observatory)  in  reference  to  this  subject.' — I  agreed 
with  Schumacher  in  giving  no  medal  to  Mr  G.  P.  Bond ;  his 
comet  was  found  to  be  Petersen's.  Five  medals  were  awarded 
for  comets  in  1847  (Hind,  Colla,  Mauvais,  Brorsen,  Schweizer). 
—The  Liverpool  Observatory  was  finished  this  year :  and  the 
thanks  of  the  Town  Council  were  presented  to  me. — Respect- 
ing Fallows's  Observations  at  the  Cape  of  Good  Hope :  I 
had  received  the  Admiralty  sanction  for  proceeding  with 
calculations  in  1846,  and  I  employed  computers  as  was  con- 
venient. On  July  20th  of  this  year  1  was  ready  with  final 
results,  and  began  to  make  enquiries  about  Fallows's  personal 
history,  and  the  early  history  of  the  Cape  Observatory.  On 
Oct.  23rd  I  applied  for  sanction  for  printing,  which  was  given, 
and  the  work  was  soon  finished  off,  in  the  Astronomical 
Society's  Memoirs. — In  the  month  of  March  I  had  com- 
menced correspondence  with  various  persons  on  the  imperfect 


202  GEORGE   BIDDELL   AIRY. 

state  of  publication  of  the  British  Survey.  Sheets  of  the 
Map  were  issued  by  scores,  but  not  one  of  them  had  an  indi- 
cation of  latitude  or  longitude  engraved.  I  knew  that  great 
pains  had  been  taken  in  giving  to*  the  principal  triangulation 
a  degree  of  accuracy  never  before  reached,  and  in  fixing  the 
astronomical  latitudes  of  many  stations  with  unequalled  pre- 
cision. Finally  1  prepared  for  the  Council  "of  the  Royal 
Society  a  very  strong  representation  on  these  subjects,  which 
was  adopted  and  presented  to  the  Government.  It  was 
entirely  successful,  and  the  Maps  were  in  future  furnished 
with  latitude  and  longitude  lines. — I  was  elected  President 
of  the  Royal  Astronomical  Society  on  Feb.  gih. — In  June  I 
went  with  Sheepshanks  to  see  some  of  the  operation  of 
measuring  a  Base  on  Salisbury  Plain.  The  following  extract 
from  a  letter  to  his  wife  dated  1849,  June  2/th,  relates  to  this 
expedition  :  '  In  the  morning  we  started  before  eight  in  an 
open  carriage  to  the  Plain  :  looking  into  Old  Sarum  on  our 
way.  The  Base  is  measured  on  what  I  should  think  a  most 
unfavourable  line,  its  north  end  (from  which  they  have  begun 
now,  in  verification  of  the  old  measure)  being  the  very  highest 
point  in  the  whole  plain,  called  Beacon  Hill.  The  soldiers 
measure  only  252  feet  in  a  day,  so  it  will  take  them  a  good 
while  to  measure  the  whole  seven  miles.  While  we  were 
there  Col.  Hall  (Colby's  successor)  and  Yolland  and  Cosset 
came.'" 

Of  private  history  :  "  I  made  short  visits  to  Playford  in 
January,  April  and  July.  From  July  28th  to  Sept.  I2th  I 
made  an  expedition  with  my  wife  to  Orkney  and  Shetland. — 
From  Dec.  24th  to  26th  I  was  at  Hawkhurst,  on  a  visit  to 
Sir  John  Herschel." 

1850 

"The  Report  to  the  Board  of  Visitors  opens  with  the 
following  paragraph  :  '  In  recording  the  proceedings  at  the 
Royal  Observatory  during  the  last  year,  I  have  less  of  novelty 


AT   GREENWICH   OBSERVATORY — 1846   TO    1856.       203 

to  communicate  to  the  Visitors  than  in  the  Reports  of  several 
years  past.  Still  I  trust  that  the  present  Report  will  not  be 
uninteresting ;  as  exhibiting,  I  hope,  a  steady  and  vigorous 
adherence  to  a  general  plan  long  since  matured,  accompanied 
with  a  reasonable  watchfulness  for  the  introduction  of  new 
instruments  and  new  methods  when  they  may  seem  desirable.' 
— Since  the  introduction  of  the  self-registering  instruments  a 
good  many  experiments  had  been  made  to  obtain  the  most 
suitable  light,  and  the  Report  states  that  '  No  change  what- 
ever has  been  made  in  these  instruments,  except  by  the 
introduction  of  the  light  of  coal-gas  charged  with  the  vapour 
of  coal-naptha,  for  photographic  self-registration  both  of  the 
magnetic  and  of  the  meteorological  instruments.... The  chemi- 
cal treatment  of  the  paper  is  now  so  well  understood  by  the 
Assistants  that  a  failure  is  almost  unknown.  And,  generally 
speaking,  the  photographs  are  most  beautiful,  and  give  con- 
ceptions of  the  continual  disturbances  in  terrestrial  magnetism 
which  it  would  be  impossible  to  acquire  from  eye-observa- 
tion.'— Amongst  the  General  Remarks  of  the  Report  it  is 
stated  that  '  There  are  two  points  which  have  distinctly 
engaged  my  attention.  The  first  of  these  is,  the  introduction 
of  the  American  method  of  observing  transits,  by  completing 
a  galvanic  circuit  by  means  of  a  touch  of  the  finger  at  the 
instant  of  appulse  of  the  transiting  body  to  the  wire  of  the 
instrument,  which  circuit  will  then  animate  a  magnet  that 
will  make  an  impression  upon  a  moving  paper.  After  careful 
consideration  of  this  method,  I  am  inclined  to  believe  that,  in 
Prof.  Mitchell's  form,  it  does  possess  the  advantages  which 
have  been  ascribed  to  it,  and  that  it  may  possess  peculiar 
advantages  in  this  Observatory,  where  the  time-connection  of 
transits  made  with  two  different  instruments  (the  Transit  and 
the  Altazimuth)  is  of  the  highest  importance.... The  second 
point  is,  the  connection  of  the  Observatory  with  the  galvanic 
telegraph  of  the  South  Eastern  Railway,  and  with  other  lines 
of  galvanic  wire  with  which  that  telegraph  communicates.  I 
had  formerly  in  mind  only  the  connection  of  this  Observatory 


204  GEORGE   BIDDELL   AIRY. 


with  different  parts  of  the  great  British  island  :  but  I  now 
think  it  possible  that  our  communications  may  be  extended 
far  beyond  its  shores.  The  promoters  of  the  submarine  tele- 
graph are  very  confident  of  the  practicability  of  completing  a 
galvanic  connection  between  England  and  France :  and  I 
now  begin  to  think  it  more  than  possible  that,  within  a  few 
years,  observations  at  Paris  and  Brussels  may  be  registered 
on  the  recording  surfaces  at  Greenwich,  and  vice  versa.' — 
Prof.  Hansen  was  engaged  in  forming  Lunar  Tables  from  his 
Lunar  Theory,  but  was  stopped  for  want  of  money.  On 
Mar.  /th  I  represented  this  privately  to  Mr  Baring,  First 
Lord  of  the  Admiralty ;  and  on  Mar.  3Oth  I  wrote  officially 
to  the  Admiralty,  soliciting  £150  with  the  prospect,  if  neces- 
sary, of  making  it  £200.  On  Apr.  loth  the  Admiralty  gave 
their  assent.  The  existence  of  Hansen's  Lunar  Tables  is  due 
to  this  grant. — The  King  of  Denmark's  Medal  for  Comets 
was  discontinued,  owing  to  the  difficulties  produced  by  the 
hostility  of  Prussia. — On  Aug.  ist  I  gave  to  the  Treasury  my 
opinion  on  the  first  proposal  for  a  large  reflector  in  Australia : 
it  was  not  strongly  favourable. — In  August,  being  (with  my 
wife  and  Otto  Struve)  on  a  visit  to  Lady  Breadalbane  at 
Taymouth  Castle,  I  examined  the  mountain  Schehallien. — 
As  in  other  years,  I  reported  on  several  Papers  for  the  Royal 
Society,  and  took  part  in  various  business  for  them. — In  the 
Royal  Astronomical  Society  I  had  much  official  business,  as 
President. — In  March  I  communicated  to  the  Athenaeum  my 
views  on  the  Exodus  of  the  Israelites :  this  brought  me  into 
correspondence  with  Miss  Corbaux,  Robert  Stephenson, 
Capt.  Vetch,  and  Prof.  J.  D.  Forbes. — In  December  I  went 
to  the  London  Custom  House,  to  see  Sir  T.  Freemantle 
(Chairman  of  Customs),  and  to  see  how  far  decimal  sub- 
divisions were  used  in  the  Custom  House." 

Of  private  history:  "From  Mar.  iQth  to  22nd  I  was  on 
an  expedition  to  Folkestone,  Dover,  Dungeness,  &c. — From 
Apr.  3rd  to  8th  at  Playford,  and  again  for  short  periods  in 
June  and  July. — From  Aug.  ist  to  Sept  5th  I  was  travelling 


AT   GREENWICH  OBSERVATORY— 1846   TO    1856.       2O5 

in  Scotland  with  my  wife  and  Otto  Struve  (for  part  of  the 
time).  At  Edinburgh  I  attended  the  Meeting  of  the  British 
Association,  and  spoke  a  little  in  Section  A.  I  was  nomi- 
nated President  for  1851  at  Ipswich.  We  travelled  to  Cape 
Wrath  and  returned  by  Inverness  and  the  Caledonian  Canal. 
— I  was  at  Play  ford  for  a  short  time  in  October  and  Decem- 
ber." 


1851 

"  In  this  year  the  great  shed  was  built  (first  erected  on  the 
Magnetic  Ground,  and  about  the  year  1868  transferred  to  the 
South  Ground). — The  chronometers  were  taken  from  the  old 
Chronometer  Room  (a  room  on  the  upper  story  fronting  the 
south,  now,  1872,  called  Library  2)  and  were  put  in  the  room 
above  the  Computing  Room  (where  they  remained  for  10  or 
12  years,  I  think) :  it  had  a  chronometer-oven  with  gas-heat, 
erected  in  1850. — The  following  passage  is  quoted  from  the 
Report  to  the  Visitors  : — '  As  regards  Meridional  Astronomy 
our  equipment  may  now  be  considered  complete.  As  I  have 
stated  above,  an  improvement  might  yet  be  made  in  our 
Transit  Circle ;  nevertheless  I  do  not  hesitate  to  express  my 
belief  that  no  other  existing  meridional  instrument  can  be 
compared  with  it.  This  presumed  excellence  has  not  been 
obtained  without  much  thought  on  my  part  and  much  anxiety 
on  the  part  of  the  constructors  of  the  instrument  (Messrs 
Ransomes  and  May,  and  Mr  Simms).  But  it  would  be  very 
unjust  to  omit  the  further  statement  that  the  expense  of  the 
construction  has  considerably  exceeded  the  original  estimate, 
and  that  this  excess  has  been  most  liberally  defrayed  by  the 
Government.' — In  December  Sir  John  Herschel  gave  his 
opinion  (to  the  Admiralty,  I  believe)  in  favour  of  procuring 
for  the  Cape  Observatory  a  Transit  Circle  similar  to  that  at 
Greenwich. — I  had  much  correspondence  about  sending  Pierce 
Morton  (formerly  a  pupil  of  mine  at  Cambridge,  a  clever 
gentlemanly  man,  and  a  high  wrangler,  but  somewhat  flighty) 


206  GEORGE   BIDDELL   AIRY. 

as  Magnetic  Assistant  to  the  Cape  Observatory :  he  was  with 
me  from  May  to  October,  and  arrived  at  the  Cape  on 
Nov.  27th. — I  was  much  engaged  with  the  clock  with  conical 
motion  of  pendulum,  for  'uniforrrf  movement  of  the  Chrono- 
graphic  Barrel. — Regarding  galvanic  communications  :  On 
Sept.  iQth  I  had  prepared  a  Draft  of  Agreement  with  the 
South  Eastern  Railway  Company,  to  which  they  agreed.  In 
November  I  wrote  to  Sir  T.  Baring  (First  Lord  of  the  Ad- 
miralty) and  to  the  Admiralty  for  sanction,  which  was  given 
on  Dec.  i8th.  In  December  I  had  various  communications 
about  laying  wires  through  the  Park,  &c.,  &c.,  and  correspon- 
dence about  the  possibility  of  using  sympathetic  clocks  :  in 
June,  apparently,  I  had  seen  Shepherd's  sympathetic  clock  at 
the  Great  Exhibition,  and  had  seen  the  system  of  sympathetic 
clocks  at  Pawson's,  St  Paul's  Churchyard. — In  the  last  quarter 
of  this  year  I  was  engaged  in  a  series  of  calculations  of  chrono- 
logical eclipses.  On  Sept.  3<Dth  Mr  Bosanquet  wrote  to  me 
about  the  Eclipse  of  Thales,  and  I  urged  on  the  computations 
related  to  it,  through  Mr  Breen.  In  October  the  eclipse  of 
Agathocles  (the  critical  eclipse  for  the  motion  of  the  Moon's 
node)  was  going  on.  In  October  Hansteen  referred  me  to 
the  darkness  at  Stiklastad. — I  went  to  Sweden  to  observe  the 
total  eclipse  of  July  28th,  having  received  assistance  from  the 
Admiralty  for  the  journeys  of  myself,  Mr  Dunkin,  Mr  Hum- 
phreys and  his  friend,  and  Capt.  Blackwood.  I  had  prepared 
a  map  of  its  track,  in  which  an  important  error  of  the  Berliner 
Jahrbuch  (arising  from  neglect  of  the  earth's  oblateness)  was 
corrected.  I  gave  a  lecture  at  the  Royal  Institution,  in 
preparation  for  the  eclipse,  and  drew  up  suggestions  for 
observations,  and  I  prepared  a  scheme  of  observations  for 
Greenwich,  but  the  weather  was  bad.  The  official  account 
of  the  Observations  of  the  Eclipse,  with  diagrams  and  con- 
clusions, is  given  in  full  in  a  paper  published  in  the  Royal 
Astr.  Society's  Memoirs. — This  year  I  was  President  of  the 
British  Association,  at  the  Ipswich  Meeting :  it  necessarily 
produced  a  great  deal  of  business.  I  lectured  one  evening 


AT   GREENWICH    OBSERVATORY — 1846   TO    1856.        2O/ 

on  the  coming  eclipse.  Prince  Albert  was  present,  as  guest 
of  Sir  William  Middleton  :  I  was  engaged  to  meet  him  at 
dinner,  but  when  I  found  that  the  dinner  day  was  one  of  the 
principal  soiree  days,  I  broke  off  the  engagement. — On  May 
26th  I  had  the  first  letter  from  E.  Hamilton  (whom  I  had 
known  at  Cambridge)  regarding  the  selection  of  professors 
for  the  University  of  Sydney.  Herschel,  Maldon,  and  H. 
Denison  were  named  as  my  coadjutors.  Plenty  of  work  was 
done,  but  it  was  not  finished  till  1852. — In  connection  with 
the  clock  for  Westminster  Palace,  in  February  there  were 
considerations  about  providing  other  clocks  for  the  various 
buildings ;  and  this  probably  was  one  reason  for  my  examining 
Shepherd's  Clocks  at  the  Great  Exhibition  and  at  Pawson's. 
In  November  I  first  proposed  that  Mr  E.  B.  Denison  should 
be  associated  with  me.  About  the  end  of  the  year,  the 
plan  of  the  tower  was  supplied  to  me,  with  reference  to  the 
suspension  of  the  weights  and  other  particulars. — In  1850 
Admiral  Dundas  (M.P.  for  Greenwich  and  one  of  the  Board 
of  Admiralty)  had  requested  me  to  aid  the  Trustees  of  the 
Dee  Navigation  against  an  attack;  and  on  Mar.  iQth  1851  I 
went  to  Chester  to  see  the  state  of  the  river.  On  Jan.  1st 
1852  I  went  to  give  evidence  at  the  Official  Enquiry. — At  a 
discussion  on  the  construction  of  the  Great  Exhibition  build- 
ing in  the  Institution  of  Civil  Engineers,  I  expressed  myself 
strongly  on  the  faulty  principles  of  its  construction. — In  this 
year  I  wrote  my  first  Paper  on  the  landing  of  Julius  Csesar  in 
Britain,  and  was  engaged  in  investigations  of  the  geography, 
tides,  sands,  &c.,  relating  to  the  subject." 

Of  private  history  :  "  I  was  several  times  at  Playford  during 
January,  and  went  there  again  on  Dec.  23rd. — In  this  year  a 
very  heavy  misfortune  fell  on  us.  My  daughter,  Elizabeth, 
had  been  on  a  visit  to  Lady  Herschel  at  Hawkhurst,  and  on 
Apr.  2nd  Sir  J.  Herschel  wrote  to  me,  saying  that  she  was  so 
well  in  health.  She  returned  a  few  days  later,  and  from  her 
appearance  I  was  sure  that  she  was  suffering  under  deadly 
disease.  After  some  time,  an  able  physician  was  consulted, 


208  GEORGE   BIDDELL   AIRY. 

who  at  once  pronounced  it  to  be  pulmonary.  A  sea  voyage 
was  thought  desirable,  and  my  wife  took  her  to  Shetland, 
where  there  was  again  a  kind  welcome  from  Mr  Edmonston. 
But  this,  and  the  care  taken  on  her  return,  availed  nothing : 
and  it  was  determined  to  take  her  to  Madeira.  My  wife  and 
daughter  sailed  in  the  brig  '  Eclipse '  from  Southampton  on 
Dec.  nth.  The  termination  came  in  1852. — Oh  Nov.  23rd  I 
went  to  Bradfield,  near  Bury :  my  uncle,  George  Biddell,  died, 
and  I  attended  the  funeral  on  Nov.  29th. — From  July  i8th  to 
Aug.  24th  I  was  in  Sweden  for  the  Observation  of  the 
Eclipse,  and  returned  through  Holland. — In  October  I  was 
about  a  week  at  Ventnor  and  Torquay,  and  from  Dec.  7th 
to  nth  at  Southampton,  on  matters  connected  with  my 
daughter's  illness." 

The  following  extracts  are  from  letters  to  his  wife,  relating 
to  the  Observation  of  the  eclipse,  his  interview  with  the  King 
of  Sweden,  &c.,  and  his  visit  to  the  pumping  engines  at 
Haarlem : 

July  28,  half-past  10,  morning. 

The  weather  is  at  present  most  perfectly  doubtful.  Nearly  the 
whole  sky  is  closely  covered,  yet  there  is  now  and  then  a  momentary 
gleam  of  sun.  The  chances  are  greatly  against  much  of  the  eclipse 
being  seen.  All  is  arranged  to  carry  off  the  telescope,  &c.,  at  1 1  : 
they  can  be  carted  to  the  foot  of  the  hill,  and  we  have  made  out  a 
walking-pass  then  to  the  top.  We  are  to  dine  with  Mr  Dickson 
afterwards. 

July  28,  10  at  night. 

Well  we  have  had  a  glorious  day.  As  soon  as  we  started,  the 
weather  began  to  look  better.  We  went  up  the  hill  and  planted  my 
telescope,  and  the  sky  shewed  a  large  proportion  of  blue.  At  first  I 
placed  the  telescope  on  the  highest  rock,  but  the  wind  blew  almost 
a  gale,  and  shook  it  slightly  :  so  I  descended  about  8  feet  to  one 
side.  (The  power  of  doing  this  was  one  of  the  elements  in  my 
choice  of  this  station,  which  made  me  prefer  it  to  the  high  hill 
beyond  the  river.)  The  view  of  scenery  was  inexpressibly  beautiful. 


AT   GREENWICH   OBSERVATORY— 1846  TO    1856.        2OQ 

The  beginning  of  eclipse  was  well  seen.  The  sky  gradually  thickened 
from  that  time,  so  that  the  sun  was  in  whitish  cloud  at  the  totality, 
and  barely  visible  in  dense  cloud  at  the  end  of  the  eclipse.  The 
progress  of  the  eclipse  brought  on  the  wonderful  changes  that  you 
know  :  just  before  the  totality  I  saw  a  large  piece  of  blue  sky  become 
pitch  black ;  the  horror  of  totality  was  very  great ;  and  then  flashed 
into  existence  (I  do  not  know  how)  a  broad  irregular  corona  with 
red  flames  instantly  seen  of  the  most  fantastic  kind.  The  darkness 
was  such  that  my  assistant  had  very  great  trouble  in  reading  his  box 
chronometer.  (A  free-hand  explanatory  diagram  is  here  given.) 
Some  important  points  are  made  out  from  this,  ist  the  red  flames 
certainly  belong  to  the  sun.  2nd  they  certainly  are  in  some  instances 
detached.  3rd  they  are  sometimes  quite  crooked.  4th  they  seem 
to  be  connected  with  spots.  The  corona  was  brilliant  white.  One 
star  brilliant :  I  believe  Venus.  I  had  no  time  to  make  observations 
of  polarization,  &c.,  although  prepared.  When  the  totality  was  more 
than  half  over  I  looked  to  N.  and  N.W.,  and  in  these  regions  there 
was  the  fullest  rosy  day-break  light.  After  the  sun-light  reappeared, 
the  black  shadow  went  travelling  away  to  the  S.E.  exactly  like  the 
thunder-storm  from  the  Main.  The  day  then  grew  worse,  and  we 
came  home  here  (after  dinner)  in  pouring  rain. 


STOCKHOLM, 

1851,  Aug.  5- 

I  then  by  appointment  with  Sir  Edmund  Lyons  went  with  him  to 
the  Minister  for  Foreign  Affairs,  Baron  Stjerneld,  who  received  me 
most  civilly.  My  business  was  to  thank  him  for  the  orders  which 
had  been  given  to  facilitate  the  landing  of  our  telescopes,  &c.,  &c. 
He  was  quite  familiar  with  the  names  of  my  party,  Humphreys 
Milaud,  &c.,  so  that  I  trust  they  have  been  well  received  (I  have 
had  no  letter).  He  intimated,  I  suppose  at  Sir  E.  Lyons's  suggestion, 
that  perhaps  King  Oscar  might  wish  to  see  me,  but  that  it  would 
not  be  on  Tuesday.  So  I  replied  that  I  was  infinitely  flattered  and 
he  said  that  he  would  send  a  message  to  Sir  E.  Lyons  by  Tuesday 
evening.  Now  all  this  put  me  in  a  quandary  :  because  I  wanted  to 
see  Upsala,  47  miles  off :  and  the  steamboats  on  the  Malar  only  go 
in  the  morning  and  return  in  the  morning  :  and  this  was  irreconcile- 
able  with  waiting  for  his  Majesty's  appointment  which  might  be  for 
Wednesday  morning.  So  after  consultation  Sir  E.  Lyons  put  me  in 
the  hands  of  a  sort  of  courier  attached  to  the  Embassy,  and  he  pro- 
A.  B.  14 


210  GEORGE   BIDDELL   AIRY. 

cured  a  caleche,  and  I  posted  to  Upsala  yesterday  afternoon  (knock- 
ing the  people  up  at  n  at  night)  and  posted  back  this  afternoon. 
And  sure  enough  a  message  has  come  that  the  king  expects  me  at 
ii  to-morrow  morning.  -Posting  of  course  is  much  dearer  than 
steam-boat  travelling,  but  it  is  cheap  in  comparison  with  England  : 
two  horses  cost  is.  for  nearly  7  miles.  At  Upsala  there  is  a  very 
good  old  cathedral,  I  suppose  the  only  one  in  Sweden  :  and  many 
things  about  the  University  which  interested  me.  I  sent  my  card  to 
Professor  Fries,  and  he  entirely  devoted  himself  to  me  :  but  imagine 
our  conversation — he  spoke  in  Latin  and  I  in  French  :  however  we 
understood  each  other  very  well.  It  is  on  the  whole  a  dreary 
country  except  where  enlivened  by  lakes  :  some  parts  are  pine  forests 
and  birch  forests,  but  others  are  featureless  ground  with  boulder 
stones,  like  the  worst  part  of  the  Highlands. 


August  6,   Wednesday,  3  o'clock. 

I  rigged  myself  in  black  trowsers  and  white  waistcoat  and  neck- 
cloth this  morning.  Sir  Edmund  Lyons  called.  Baron  Wrede  called 
on  me  :  he  had  observed  the  Eclipse  at  Calmar  and  brought  his 
drawing,  much  like  mine.  He  conducted  me  to  the  Palace.  The 
Minister  for  Foreign  Affairs  came  to  me.  In  the  waiting-room  I  was 
introduced  to  the  Lieutenant-Governor  of  Christianstad,  who  had  had 
the  charge  of  Humphreys  and  Milaud.  He  had  placed  a  guard  of 
soldiers  round  them  while  they  were  observing.  They  saw  the 
eclipse  well.  Captain  Blackwood  went  to  Helsingborg  instead  of 
Bornholm,  and  saw  well.  I  am  sorry  to  hear  that  it  was  cloudy  at 
Christiania,  Mr  Dunkin's  station.  I  heard  some  days  ago  that  Hind 
had  lost  his  telescope,  but  I  now  heard  a  very  different  story :  that 
he  landed  at  Ystad,  and  found  a  very  bad  hotel  there :  that  he  learnt 
from  Murray  that  the  hotels  at  Carlscrona  (or  wherever  he  meant  to 
go)  were  much  worse  ;  and  so  he  grew  faint  at  heart  and  turned  back. 
I  was  summoned  in  to  the  King  and  presented  by  the  Minister 
(Stjerneld),  and  had  a  long  conversation  with  him :  on  the  eclipse, 
the  arc  of  meridian,  the  languages,  and  the  Universities.  We  spoke 
in  French.  Then  Baron  Wrede  went  with  me  to  the  Rittershus 
(House  of  Lords  or  Nobles)  in  Session,  and  to  the  Gallery  ot 
Scandinavian  Antiquities,  which  is  very  remarkable  :  the  collection 
of  stone  axes  and  chisels,  bronze  do.,  iron  do.,  ornaments,  &c.  is 
quite  amazing.  I  was  struck  with  seeing  specimens  from  a  very 


AT   GREENWICH   OBSERVATORY — 1846  TO    1856.        211 

distant  age  of  the  Maid  of  Norway's  brooch  :  the  use  of  which  I 
explained  to  the  Director. 

I  dined  and  drove  out  with  Sir  E.  Lyons,  and  called  at  the 
houses  of  the  Baron  Stjerneld  and  of  the  Norwegian  Minister  Baron 
Due,  and  had  tea  at  the  latter.  Most  of  these  people  speak  English 
well,  and  they  seem  to  live  in  a  very  domestic  family  style.  I  should 
soon  be  quite  at  home  here:  for  I  perceive  that  my  reception  at 
Court,  &c.,  make  people  think  that  I  am  a  very  proper  sort  of 
person. 


The  extract  concerning  his  visit  to  the  Pumping-Engines 
at  Haarlem  is  as  follows : 

LEYDEN, 
1851,  August  20,   Wednesday. 

I  went  to  see  the  great  North  Holland  Canal,  and  went  a  mile 
or  two  in  a  horse-drawn-boat  upon  it :  a  very  comfortable  convey- 
ance. Saw  windmills  used  for  sawing  timber  and  other  purposes,  as 
well  as  some  for  grinding  and  many  for  draining.  Yesterday  at  half- 
past  one  I  went  by  railway  to  Haarlem.  I  did  not  look  at  anything 
in  the  town  except  going  through  it  and  seeing  that  it  is  a  curious 
fantastic  place,  but  I  drove  at  once  to  the  burgomaster  to  ask  per- 
mission to  visit  one  of  the  three  great  pumping  engines  for  draining 
the  immense  Haarlem  lake,  and  then  drove  to  it.  Imagine  a  round 
tower  with  a  steam-cylinder  in  its  center;  and  the  piston  which 
works  up-and-down,  instead  of  working  one  great  beam  as  they 
usually  do,  works  eight,  poking  out  on  different  sides  of  the  round 
tower,  and  each  driving  a  pump  6  feet  in  diameter.  I  am  glad  to 
have  seen  it.  Then  by  railway  here. 


1852 

"  Galvanic  communication  was  now  established  with 
Lewisham  station  (thus  giving  power  of  communicating  with 
London,  Deal,  &c.). — From  the  Report  to  the  Board  of 
Visitors  it  appears  that,  in  the  case  of  the  Transit  Circle, 
the  azimuth  of  the  Instrument  as  determined  by  opposite 

14—2 


212  GEORGE   BIDDELL  AIRY. 

passages  of  the  Pole  Star  had  varied  four  seconds;  and  in 
the  case  of  the  Altazimuth,  there  was  a  discordance  in  the 
azimuthal  zeros  of  the  Instrument,  as  determined  from  obser- 
vations of  stars.  In  both  cases  it  was  concluded  that  the 
discordances  arose  from  small  movements  of  the  ground. — 
Under  the  head  of  'General  Remarks'  in  the  Report,  the 
following  paragraph  occurs  :  *  It  will  be  perceived  that  the 
number  of  equatoreal  observations  made  here  at  present  is 
small :  and  that  they  are  rarely  directed  to  new  comets  and 
similar  objects  which  sometimes  excite  considerable  interest. 
This  omission  is  intentional.  It  is  not  because  the  instru- 
mental means  are  wanting  (for  our  Equatoreals,  though  not 
comparable  to  those  of  either  Cambridge,  or  of  Pulkowa,  are 
fully  equal  to  those  usually  directed  to  such  objects),  but  it 
is  because  these  observations  are  most  abundantly  supplied 
from  other  observatories,  public  and  private,  and  because  the 
gain  to  those  observations  from  our  taking  a  part  in  them 
would,  probably,  be  far  less  than  the  loss  to  the  important 
class  of  observations  which  we  can  otherwise  follow  so  well. 
Moreover,  I  am  unwilling  to  take  any  step  which  could  be 
interpreted  as  attempting  to  deprive  the  local  and  private 
observatories  of  honours  which  they  have  so  nobly  earned. 
And,  finally,  in  this  act  of  abstinence,  I  am  desirous  of  giving 
an  example  of  adhesion  to  one  principle  which,  I  am  con- 
fident, might  be  extensively  followed  with  great  advantage 
to  astronomy  : — the  principle  of  division  of  labour.' — Dis- 
coveries of  small  planets  were  now  not  infrequent :  but  the 
only  one  of  interest  to  me  is  Melpomene,  for  the  following 
reason.  On  1852  June  24  I  lost  my  most  dear,  amiable, 
clever  daughter  Elizabeth :  she  died  at  Southampton,  two 
days  after  landing  from  Madeira.  On  that  evening  Mr  Hind 
discovered  the  planet ;  and  he  requested  me  to  give  a  name. 
I  remembered  Horace's  '  Praecipe  lugubres  cantus,  Mel- 
pomene,' and  Cowley's  '  I  called  the  buskin'd  muse  Mel- 
pomene and  told  her  what  sad  story  I  would  write,'  and 
suggested  Melpomene,  or  Penthos  :  Melpomene  was  adopted. 


AT   GREENWICH   OBSERVATORY — 1846   TO    1856.        213 

— The  first  move  about  the  Deal  Time  Ball  was  in  a  letter 
from  Commander  Baldock  to  the  Admiralty,  suggesting  that 
a  Time  Ball,  dropped  by  galvanic  current  from  Greenwich, 
should  be  attached  to  one  of  the  South  Foreland  Lighthouses. 
The  Admiralty  sent  this  for  my  Report.  I  went  to  the  place, 
and  I  suggested  in  reply  (Nov.  15th)  that  a  better  place 
would  be  at  an  old  signal  station  on  the  chalk  downs.  The 
decisive  change  from  this  was  made  in  1853. — As  the  result 
of  my  examination  and  enquiries  into  the  subject  of  sym- 
pathetic clocks,  I  established  8  sympathetic  clocks  in  the 
Royal  Observatory,  one  of  which  outside  the  entrance  gate 
had  a  large  dial  with  Shepherd's  name  as  Patentee.  Ex- 
ception was  taken  to  this  by  the  solicitor  of  a  Mr  Bain  who 
had  busied  himself  about  galvanic  clocks.  After  much  cor- 
respondence I  agreed  to  remove  Shepherd's  name  till  Bain 
had  legally  established  his  claim.  This  however  was  never 
done:  and  in  1853  Shepherd's  name  was  restored. — In  Nov. 
1851,  Denison  had  consented  to  join  me  in  the  preparation 
of  the  Westminster  Clock.  In  Feb.  1852  we  began  to  have 
little  disagreements.  However  on  Apr.  6th  I  was  going  to 
Madeira,  and  requested  him  to  act  with  full  powers  from  me. 
— I  communicated  to  the  Royal  Society  my  Paper  on  the 
Eclipses  of  Agathocles,  Thales,  and  Xerxes. — In  the  British 
Association,  I  had  presided  at  the  Ipswich  Meeting  in  1851, 
and  according  to  custom  I  ought  to  attend  at  the  1852 
Meeting  (held  at  Belfast)  to  resign  my  office.  But  I  was 
broken  in  spirit  by  the  death  of  my  daughter,  and  the  thing 
generally  was  beyond  my  willing  enterprise.  I  requested 
Sir  Roderick  Murchison  to  act  generally  for  me:  which  he 
did,  as  I  understood,  very  gracefully. — In  this  year  a  proposal 
was  made  by  the  Government  for  shifting  all  the  Meeting 
Rooms  of  the  Scientific  Societies  to  Kensington  Gore,  which 
was  stoutly  resisted  by  all,  and  was  finally  abandoned." 

Of  private  history :  "  I  was  at  Playford  in  January,  and 
went  thence  to  Chester  on  the  enquiry  about  the  tides  of 
the  Dee;  and  made  excursions  to  Halton  Castle  and  to 


214  GEORGE   BIDDELL  AIRY. 

Holyhead. — From  Apr.  8th  to  May  I4th  I  was  on  the 
voyage  to  and  from  Madeira,  and  on  a  short  visit  to  my  wife 
and  daughter  there. — On  June  23rd  I  went  to  Southampton 
to  meet  my  wife  and  daughter  just  landed  from  Madeira :  on 
June  24th  my  dear  daughter  Elizabeth  died :  she  was  buried 
at  Playford  on  June  29th. — I  was  at  Playford  also  in  July 
and  December. — From  Sept.  i6th  to  24th  I  went  to  Cumber- 
land, via  Fleetwood  and  Peel." 


1853 

"On  May  3rd  1853  I  issued  an  address  to  the  individual 
Members  of  the  Board  of  Visitors,  proposing  the  extension  of 
the  Lunar  Reductions  from  1830.  From  this  it  appears  that 
'Through  the  whole  period  (from  1830  to  1853),  tne  places  of 
the  Moon,  deduced  from  the  observations,  are  compared  with 
the  places  computed  in  the  Nautical  Almanac :  that  is,  with 
Burckhardt's  tables,  which  have  been  used  for  many  years  in 

computing   the   places   of   the    Nautical   Almanac Very 

lately,  however,  Mr  Adams  has  shewn  that  Burckhardt's 
Parallax  is  erroneous  in  formula  and  is  numerically  incorrect, 
sometimes  to  the  amount  of  seven  seconds.  In  consequence 
of  this,  every  reduction  of  the  Observations  of  the  Moon, 
from  1830  to  the  present  time,  is  sensibly  erroneous.  And 
the  error  is  of  such  a  nature  that  it  is  not  easy,  in  general,  to 
introduce  its  correction  by  any  simple  process.... The  number 
of  observations  to  the  end  of  1851  (after  which  time  the 
parallax  will  be  corrected  in  the  current  reductions)  is  about 
2560.  An  expense  approaching  to  £400  might  be  incurred 
in  their  reduction.'  Subsequently  I  made  application  to  the 
Admiralty,  and  the  ^"400  was  granted  on  Dec.  I2th. — In  the 
Report  to  the  Visitors  it  is  stated  that  with  regard  to  the 
Transit  Circle,  changes  are  under  contemplation  in  its  re- 
flection-apparatus :  one  of  these  changes  relates  to  the  ma- 
terial of  the  trough.  '  Several  years  ago,  when  I  was  at 
Hamburgh,  my  revered  friend  Prof.  Schumacher  exhibited  to 


AT   GREENWICH   OBSERVATORY — 1846  TO    1856.        215 

me  the  pacifying  effect  of  a  copper  dish  whose  surface  had 

been  previously  amalgamated  with  quicksilver The  Rev. 

Charles  Pritchard  has  lately  given  much  attention  to  this 
curious  property  of  the  metals,  and  has  brought  the  practical 
operation  of  amalgamation  to  great  perfection.  Still  it  is 
not  without  difficulty,  on  account  of  a  singular  crystallization 
of  the  amalgam.' — With  regard  to  the  Chronograph,  the 
Report  states :  '  The  Barrel  Apparatus  for  the  American 

method  of  observing  transits  is  not  yet  brought  into  use I 

have,  however,  brought  it  to  such  a  state  that  I  am  beginning 
to  try  whether  the  Barrel  moves  with  sufficient  uniformity  to 
be  itself  used  as  the  Transit  Clock.  This,  if  perfectly  se- 
cured, would  be  a  very  great  convenience,  but  I  am  not  very 
sanguine  on  that  point.' — A  change  had  been  made  in  the 
Electrometer-apparatus :  '  A  wire  for  the  collection  of  atmo- 
spheric electricity  is  now  stretched  from  a  chimney  on  the 
north-west  angle  of  the  leads  of  the  Octagon  Room  to  the 
Electrometer  pole.... There  appears  to  be  no  doubt  that  a 
greater  amount  of  electricity  is  collected  by  this  apparatus 
than  by  that  formerly  in  use.' — As  regards  the  Magnetical 
Observations  :  '  The  Visitors  at  their  last  Meeting,  expressed 
a  wish  that  some  attempt  should  be  made  to  proceed  further 
in  the  reduction  or  digest  of  the  magnetical  results,  if  any 
satisfactory  plan  could  be  devised.  I  cannot  say  that  I  have 
yet  satisfied  myself  on  the  propriety  of  any  special  plan 
that  I  have  examined....!  must,  however,  confess  that,  in 
viewing  the  capricious  forms  of  the  photographic  curves,  my 
mind  is  entirely  bewildered,  and  I  sometimes  doubt  the 
possibility  of  extracting  from  them  anything  whatever  which 
can  be  considered  trustworthy.' — Great  progress  had  been 
made  with  the  distribution  of  time.  'The  same  Normal 
Clock  maintains  in  sympathetic  movement  the  large  clock  at 
the  entrance  gate,  two  other  clocks  in  the  Observatory,  and  a 
clock  at  the  London  Bridge  Terminus  of  the  South-Eastern 
Railway.... It  sends  galvanic  signals  every  day  along  all  the 
principal  railways  diverging  from  London.  It  drops  the 


2l6  GEORGE   BUJDELL  AIRY. 

Greenwich  Ball,  and  the  Ball  on  the  Offices  of  the  Electric 
Telegraph  Company  in  the  Strand;... All  these  various  effects 
are  produced  without  sensible  error  of  time;  and  I  cannot 
but  feel  a  satisfaction  in  thinking^that  the  Royal  Observatory 
is  thus  quietly  contributing  to  the  punctuality  of  business 
through  a  large  portion  of  this  busy  country.  I  have  the 
satisfaction  of  stating  to  the  Visitors  that  the  Lords  Com- 
missioners of  the  Admiralty  have  decided  on  the  erection  of 
a  Time-Signal  Ball  at  Deal,  for  the  use  of  the  shipping  in  the 
Downs,  to  be  dropped  every  day  by  a  galvanic  current  from 
the  Royal  Observatory.  The  construction  of  the  apparatus 
is  entrusted  to  me.  Probably  there  is  no  roadstead  in  the 
world  in  which  the  knowledge  of  true  time  is  so  important.' 
— The  Report  includes  an  account  of  the  determination  of 
the  Longitude  of  Cambridge  Observatory  by  means  of  gal- 
vanic signals,  which  appear  to  have  been  perfectly  successful. 
— Under  the  head  of  General  Remarks  the  following  passage 
appears :  '  The  system  of  combining  the  labour  of  unattached 
computers  with  that  of  attached  Assistants  tends  materially 
to  strengthen  our  powers  in  everything  relating  to  computa- 
tion. We  find  also,  among  the  young  persons  who  are 
engaged  merely  to  serve  as  computers,  a  most  laudable 
ambition  to  distinguish  themselves  as  observers ;  and  thus 
we  are  always  prepared  to  undertake  any  observations  which 
may  be  required,  although  necessarily  by  an  expenditure  of 
strength  which  would  usually  be  employed  on  some  other 
work.' — Considerable  work  was  undertaken  in  preparing  a 
new  set  of  maps  of  our  buildings  and  grounds. — On  Apr.  23rd 
there  was  a  small  fire  in  the  magnetic  observatory,  which  did 
little  mischief. — In  December  I  wrote  my  description  of  the 
Transit  Circle.— Lieut.  Stratford,  the  Editor  of  the  Nautical 
Almanac,  died,  and  there  was  some  competition  for  the  office. 
I  was  willing  to  take  it  at  a  low  rate,  for  the  addition  to  my 
salary:  Mr  Main — and  I  think  Mr  Glaisher — were  desirous 
of  exchanging  to  it  :  Prof.  Adams  was  anxious  for  it.  The 
Admiralty  made  the  excellent  choice  of  Mr  Hind. — In 


AT   GREENWICH   OBSERVATORY— 1846   TO    1856.        2i; 

October  Faraday  and  I,  at  Lothbury,  witnessed  some  re- 
markable experiments  by  Mr  Latimer  Clark  on  a  galvanic 
current  carried  four  times  to  and  from  Manchester  by  sub- 
terranean wires  (more  than  2000  miles)  shewing  the  retarda- 
tion of  visible  currents  (at  their  maximum  effect)  and  the 
concentration  of  active  power.  I  made  investigations  of  the 
velocity  of  the  Galvanic  Current. — I  was  engaged  on  the 
preliminary  enquiries  and  arrangements  for  the  Deal  Time 
Ball. — With  respect  to  the  Westminster  Clock  ;  an  angry 
paper  was  issued  by  Mr  Vulliamy.  In  October  I  expostu- 
lated with  Denison  about  his  conduct  towards  Sir  Charles 
Barry:  on  November  7th  I  resigned. — On  Feb.  nth  I  was 
elected  President  of  the  Royal  Astronomical  Society. — In 
the  Royal  Institution  I  lectured  on  the  Ancient  Eclipses. — 
On  Dec.  I5th  I  was  elected  to  the  Academy  of  Brussels. — 
After  preliminary  correspondence  with  Sir  W.  Molesworth 
(First  Commissioner  of  Works,  &c.)  and  Sir  Charles  Barry 
(Architect  of  the  Westminster  Palace),  I  wrote,  on  May  I4th, 
to  Mr  Gladstone  about  depositing  the  four  Parliamentary 
Copies  of  Standards,  at  the  Royal  Observatory,  the  Royal 
Mint,  the  Royal  Society,  and  within  a  wall  of  Westminster 
Palace.  Mr  Gladstone  assented  on  June  23rd. — On  Mar. 
26th  I  wrote  to  Mr  Gladstone,  proposing  to  take  advantage 
of  the  new  copper  coinage  for  introducing  the  decimal 
system.  I  was  always  strenuous  about  preserving  the 
Pound  Sterling.  On  May  loth  I  attended  the  Committee 
of  the  House  of  Commons  on  decimal  coinage  :  and  in  May 
and  September  I  wrote  letters  to  the  Athenaeum  on  decimal 
coinage. — I  had  always  something  on  hand  about  Tides.  A 
special  subject  now  was,  the  cry  about  intercepting  the  tidal 
waters  of  the  Tyne  by  the  formation  of  the  Jarrow  Docks,  in 
Jarrow  Slake ;  which  fear  I  considered  to  be  ridiculous." 

Of  private  history:  "From  Jan.  i5th  to  24th  I  was  at 
Playford. — On  Mar.  4th  I  went  to  Dover  to  try  time-signals. 
— From  June  24th  to  Aug.  6th  I  was  at  Little  Braithwaite 
near  Keswick,  where  I  had  hired  a  house,  and  made  expedi- 


2l8  GEORGE    BIDDELL   AIRY. 

tions  with  members  of  my  family  in  all  directions.  On  July 
28th  I  went,  with  my  son  Wilfrid,  by  Workington  and  Mary- 
port  to  Rose  Castle,  the  residence  of  Bishop  Percy  (the 
Bishop  of  Carlisle),  and  on  to  Carlisle  and  Newcastle,  looking 
at  various  works,  mines,  &c. — On  Dec.  24th  I  went  to 
Playford." 

1854 

The  chronograph  Barrel- Apparatus  for  the  American 
method  of  transits  had  been  practically  brought  into  use  : 
"  I  have  only  to  add  that  this  apparatus  is  now  generally 
efficient.  It  is  troublesome  in  use  ;  consuming  much  time  in 
the  galvanic  preparations,  the  preparation  of  the  paper,  and 
the  translation  of  the  puncture-indications  into  figures.  But 
among  the  observers  who  use  it  there  is  but  one  opinion  on 
its  astronomical  merits — that,  in  freedom  from  personal 
equation  and  in  general  accuracy,  it  is  very  far  superior  to 
the  observations  by  eye  and  ear." — The  printing  and  pub- 
lication of  the  Observations,  which  was  always  regarded  by 
Airy  as  a  matter  of  the  first  importance,  had  fallen  into 
arrear :  "  I  stated  in  my  last  Report  that  the  printing  of 
the  Observations  for  1852  was  scarcely  commenced  at  the 
time  of  the  last  meeting  of  the  Visitors.  For  a  long  time  the 
printing  went  on  so  slowly  that  I  almost  despaired  of  ever 
again  seeing  the  Observations  in  a  creditable  state.  After  a 
most  harassing  correspondence,  the  printers  were  at  length 

persuaded  to  move  more  actively, but  the  volume   is 

still  very  much  behind  its  usual  time  of  publication." — The 
Deal  Time-Ball  has  now  been  erected  by  Messrs  Maudslays 
and  Field,  and  is  an  admirable  specimen  of  the  workmanship 
of  those  celebrated  engineers.  The  galvanic  connection  with 
the  Royal  Observatory  (through  the  telegraph  wires  of  the 
South  Eastern  Railway)  is  perfect.  The  automatic  changes 
of  wire-communications  are  so  arranged  that,  when  the  Ball 
at  Deal  has  dropped  to  its  lowest  point,  it  sends  a  message  to 


AT   GREENWICH   OBSERVATORY— 1846   TO    1856.        2IQ 

Greenwich  to  acquaint  me,  not  with  the  time  of  the  beginning 
of  its  fall  (which  cannot  be  in  error)  but  with  the  fact  that  it 
has  really  fallen.  The  Ball  has  several  times  been  dropped 
experimentally  with  perfect  success  ;  and  some  small  official 
and  subsidiary  arrangements  alone  are  wanting  for  bringing 
it  into  constant  use." — The  operations  for  the  galvanic  deter- 
mination of  the  longitude  of  Brussels  are  described,  with  the 
following  conclusion  :  "  Thus,  about  3000  effective  signals 
were  made,  but  only  1000  of  these  were  admissible  for  the 
fundamental  objects  of  the  operation.  The  result,  I  need 
scarcely  remark,  claims  a  degree  of  accuracy  to  which  no 
preceding  determination  of  longitude  could  ever  pretend.  I 
apprehend  that  the  probable  error  in  the  difference  of  time 
corresponds  to  not  more  than  one  or  two  yards  upon  the 
Earth's  surface. — A  careful  scheme  had  been  arranged  for  the 
determination  of  the  longitude  of  Lerwick,  but  '  unfortu- 
nately, the  demand  for  chronometers  caused  by  our  large 
naval  armament  has  been  so  considerable  that  I  cannot 
reckon  on  having  at  my  disposal  a  sufficient  number  to  carry 
on  this  operation  successfully ;  and  I  have,  therefore,  un- 
willingly deferred  it  to  a  more  peaceful  time.' — The  covering 
stone  of  Halley's  Tomb  in  Lee  Churchyard  was  much 
shattered,  and  I  applied  to  the  Admiralty  for  funds  for  its 
complete  restoration  :  these  were  granted  on  Feb.  3rd. — In 
this  year,  under  my  cognizance,  ;£ioo  was  added  to  the 
Hansen  grant. — I  had  much  correspondence  and  work  in 
connection  with  the  printing  of  Maclear's  work  at  the  Cape 
of  Good  Hope.  In  June,  all  accounts,  &c.  about  the  Transit 
Circle  were  closed  at  the  Admiralty,  and  the  instrument  was 
completely  mounted  at  the  Cape. — Dr  Scoresby  (who  in  his 
own  way  was  very  imperious)  had  attacked  my  methods  of 
correcting  the  compass  in  iron  ships  :  I  replied  in  a  letter  to 
the  Athenaeum  on  Oct.  i/th. — I  made  enquiries  about  opera- 
tions for  determining  the  longitude  of  Vienna,  but  was  utterly 
repelled  by  the  foreign  telegraph  offices.  —  In  the  Royal 
Astronomical  Society ;  I  prepared  the  Address  on  presenting 


220  GEORGE   BIDDELL   AIRY. 

the  Medal  to  Riimker. —  In  Melbourne  University:  The  first 
letter  received  was  from  the  Chancellor  of  the  University 
dated  Jan.  26th,  requesting  that  Sir  John  Herschel,  Prof. 
Maiden,  Mr  Lowe  (subsequently  Chancellor  of  the  Ex- 
chequer), and  I  would  select  professors.  We  had  a  great 
deal  of  correspondence,  meetings,  examination  of  testimonials, 
&c.,  and  on  August  I4th  we  agreed  on  Wilson,  Rowe,  McCoy, 
and  Hearn. — On  Feb.  i/th  I  received  the  Prussian  Order  of 
Merit. — I  had  correspondence  with  the  Treasury  on  the  scale 
to  be  adopted  for  the  Maps  of  the  British  Survey.  I  proposed 
3^0,  and  for  some  purposes  -^fa. — I  printed  a  Paper  on  the 
Deluge,  in  which  I  shewed  (I  believe  to  certainty)  that  the 
Deluge  of  Genesis  was  merely  a  Destructive  Flood  of  the 
Nile. — Being  well  acquainted  with  the  mountains  of  Cumber- 
land, I  had  remarked  that  a  '  man  '  or  cairn  of  stones  erected 
by  the  Ordnance  Surveyors  on  the  Great  Gable  had  covered 
up  a  curious  natural  stone  trough,  known  as  one  of  the 
remarkable  singularities  of  the  country.  This  year,  without 
giving  any  notice  to  the  Ordnance  Surveyors,  I  sent  two 
wallers  from  Borrowdale  to  the  mountain  top,  to  remove  the 
'man'  about  10  feet  and  expose  the  trough.  Sir  Henry 
James  afterwards  approved  of  my  act,  and  refunded  the 
expense. — I  investigated  the  optical  condition  of  an  eye  with 
conical  cornea. 

"  The  Harton  Colliery  Experiment :  I  had  long  wished  to 
repeat  the  experiment  which  I  had  attempted  unsuccessfully 
in  1826  and  1828,  of  determining  by  pendulum-vibrations  the 
measure  of  gravity  at  the  bottom  of  a  mine.  Residing  near 
Keswick  this  summer,  and  having  the  matter  in  my  mind,  I 
availed  myself  of  an  introduction  from  Dr  Leitch  to  some 
gentlemen  at  South  Shields,  for  inspection  of  the  Harton 
Colliery.  .1  judged  that  it  would  answer  pretty  well.  I  find 
that  on  Aug.  nth  I  wrote  to  Mr  Anderson  (lessee  of  the 
mine),  and  on  the  same  day  to  the  Admiralty  requesting 
authority  to  employ  a  Greenwich  Assistant,  and  requesting 
;£ioo  for  part  payment  of  expenses.  On  August  i6th  the 


AT   GREENWICH   OBSERVATORY — 1846   TO    1856.        221 

Admiralty  assent.  There  were  many  preparations  to  be 
made,  both  personal  and  instrumental.  My  party  con- 
sisted of  Dunkin  (Superintendant),  Ellis,  Criswick,  Simmons, 
Pogson,  and  Riimker:  I  did  not  myself  attend  the  detail  of 
observations.  The  observations  began  on  Oct.  2nd  and 
ended  on  Oct.  2ist:  supplementary  observations  were  sub- 
sequently made  at  Greenwich  for  examining  the  coefficient 
of  temperature-correction.  On  Oct.  24th  I  gave  a  Lecture 
at  South  Shields  on  the  whole  operation.  In  '  Punch '  of 
Nov.  1 8th  there  was  an  excellent  semi-comic  account  of  the 
experiment,  which  as  I  afterwards  found  was  written  by  Mr 
Percival  Leigh." 

Of  private  history  :  "On  Jan.  i8th  I  returned  from  Play- 
ford.  From  Mar.  loth  to  I3th  I  was  at  Deal,  and  visited  Sir 
John  Herschel  at  Hawkhurst. — From  June  28th  to  Aug.  7th 
I  was  staying  with  my  family  at  The  Grange,  in  Borrowdale 
near  Keswick :  and  also  made  an  expedition  to  Penrith, 
Carlisle,  Newcastle,  Jarrow,  &c. ;  and  descended  the  Harton 
Pit. — In  September  and  also  in  October  I  was  at  South 
Shields  on  the  Harton  Experiments. — From  Dec.  I4th  to  i8th 
I  was  at  Cambridge,  and  on  the  26th  I  went  to  Playford." 

The  following  letter,  written  in  answer  to  a  lady  who 
had  asked  him  to  procure  permission  from  Lord  Rosse  for 
her  to  observe  with  his  telescope,  is  characteristic : 

ROYAL  OBSERVATORY,  GREENWICH. 

1854,  September  20. 

DEAR  MADAM, 

The  state  of  things  with  regard  to  Lord  Rosse's  Tele- 
scope is  this.  If  a  night  is  fine,  it  is  wanted  for  his  use  or  for  the 
use  of  professional  astronomers.  If  it  is  not  fine,  it  is  of  no  use  to 
anybody.  Now  considering  this,  and  considering  that  the  appropria- 
tion of  the  telescope  on  a  fine  night  to  any  body  but  a  technical 
astronomer  is  a  misapplication  of  an  enormous  capital  of  money  and 
intellect  which  is  invested  in  this  unique  instrument — it  is  against  my 
conscience  to  ask  Lord  Rosse  to  place  it  at  the  service  of  any  person 


222  GEORGE   BIDDELL  AIRY. 

except  an  experienced  astronomer.  No  introduction,  I  believe,  is 
necessary  for  seeing  it  in  the  day-time.  The  instrument  stands  un- 
enclosed in  the  Castle  Demesne,  to  which  strangers  are  admitted 
without  question,  I  believe...  ..........  .^. 

Faithfully  yours, 

G.  B.  AIRY. 


1855 

"  On  May  Qth  it  was  notified  to  me  (I  think  through  the 
Hydrographer)  that  the  Admiralty  were  not  unwilling  to 
increase  my  salary.  I  made  application  therefore  ;  and  on 
Jan.  2  ist  1856  Sir  Charles  Wood  notified  to  me  that  the 
Admiralty  consented  to  have  it  raised  from  ;£8oo  to  .£1000.  — 
In  the  Report  to  the  Board  of  Visitors  it  appears  that  *  At 
the  instance  of  the  Board  of  Trade,  acting  on  this  occasion 
through  a  Committee  of  the  Royal  Society,  a  model  of  the 
Transit  Circle  (with  the  improvement  of  perforated  cube,  &c. 
introduced  in  the  Cape  Transit  Circle)  has  been  prepared  for 
the  Great  Exhibition  at  Paris.'  —  Under  the  head  of  Reduc- 
tion of  Astronomical  Observations  it  is  stated  that  '  During 
the  whole  time  of  which  I  have  spoken,  the  galvanic-contact 
method  has  been  employed  for  transits,  with  the  exception  of 
a  few  days,  when  the  galvanic  apparatus  was  out  of  order. 
From  the  clock  errors,  I  have  deduced  the  personal  equations 
of  the  observers  in  our  usual  way.  .  .  .  The  result  is  that  the 
magnitude  of  the  personal  equations  in  the  galvanic-touch 
method  is  not  above  half  of  that  in  the  eye  and  ear  method.'  — 
With  regard  to  the  Reduction  of  the  Magnetical  Observations, 
'  I  have  not  yet  felt  sufficiently  satisfied  with  any  pro- 
posed method  of  discussing  the  magnetic  results  to  devote 
any  time  to  their  further  treatment.'  —  'The  Time-Signal 
Ball  at  Deal  was  brought  into  regular  use  at  the  beginning  of 
the  present  year.  In  a  short  time,  however,  its  action  was 
interrupted,  partly  by  derangement  of  the  apparatus,  and 
partly  by  the  severity  of  the  weather,  which  froze  the 


AT   GREENWICH   OBSERVATORY— 1846   TO    1856.        223 

sulphuric  acid  to  the  state  of  jelly.  I  sent  an  assistant  and 
workman  to  put  it  in  order,  and  since  that  time  it  has 
generally  acted  very  well. — Application  has  been  made  to 
me  from  one  of  the  important  offices  of  Government  (the 
Post  Office)  for  the  galvanic  regulation  of  their  clocks.— 
On  considering  the  risks  to  which  various  galvanic  com- 
munications are  liable,  and  the  financial  necessity  for 
occupying  wires  as  little  as  possible,  I  perceived  that  it  was 
necessary  to  devise  constructions  which  should  satisfy  the 
following  conditions.  First,  that  a  current  sent  once  a  day 
should  suffice  for  adjusting  the  clock,  even  if  it  had  gone  ten 
or  more  seconds  wrong.  Secondly,  that  an  occasional  failure 
of  the  current  should  not  stop  the  clock.  I  have  arranged 
constructions  which  possess  these  characters,  and  the  artist 
(Mr  C.  Shepherd)  is  now  engaged  in  preparing  estimates  of 
the  expense.  I  think  it  likely  that  this  may  prove  to  be  the 
beginning  of  a  very  extensive  system  of  clock  regulation." — 
With  respect  to  the  operations  for  determining  the  longitude 
of  Paris,  it  is  stated  that,  "  The  whole  number  of  days  of 
signal  transmission  was  eighteen,  and  the  whole  number  of 
signals  transmitted  was  2530.  The  number  of  days  con- 
sidered available  for  longitude,  in  consequence  of  transits  of 
stars  having  been  observed  at  both  Observatories,  was  twelve, 
and  the  number  of  signals  was  1703.  Very  great  care  was 
taken  on  both  sides,  for  the  adjustments  of  the  instruments. 
The  resulting  difference  of  longitude,  9™-  20-63%  is  probably 
very  accurate.  It  is  less  by  nearly  i8-  of  time  than  that 
determined  in  1825  by  rocket-signals,  under  the  superintend- 
ance  of  Sir  John  Herschel  and  Col.  Sabine.  The  time 
occupied  by  the  passage  of  the  galvanic  current  appears  to 
be  T^th  of  a  second." — With  regard  to  the  Pendulum  Experi- 
ments in  the  Harton  Colliery,  after  mentioning  that  personal 
assistance  had  been  sought  and  obtained  from  the  Observa- 
tories of  Cambridge,  Oxford,  Durham,  and  Red  Hill,  the 
Report  states  that  "  The  experiments  appear  to  have  been  in 
every  point  successful,  shewing  beyond  doubt  that  gravity  is 


224  GEORGE   BIDDELL  AIRY. 


increased  at  the  depth  of  1260  feet  by  r^o^th  part.  I  trust 
that  this  combination  may  prove  a  valuable  precedent  for 
future  associations  of  the  different  Observatories  of  the 
kingdom,  when  objects  requiring  extensive  personal  or- 
ganization shall  present  themselves."  —  On  Oct.  i8th  the 
Astronomer  Royal  printed  an  Address  to  the  Individual 
Members  of  the  Board  of  Visitors  on  the  subject  of  a  large 
new  Equatoreal  for  the  Observatory.  After  a  brief  statement 
of  the  existing  equipment  of  the  Observatory  in  respect  of 
equatoreal  instruments,  the  Address  continues  thus  :  "  It  is 
known  to  the  Visitors  that  I  have  uniformly  objected  to  any 
luxury  of  extrameridional  apparatus,  which  would  materially 
divert  us  from  a  steady  adherence  to  the  meridional  system 
which  both  reason  and  tradition  have  engrafted  on  this 
Observatory.  But  I  feel  that  our  present  instruments  are 
insufficient  even  for  my  wishes  ;  and  I  cannot  overlook  the 
consideration  that  due  provision  must  be  made  for  future 
interests,  and  that  we  are  nearer  by  twenty  years  to  the  time 
when  another  judgment  must  decide  on  the  direction  which 
shall  be  given  to  the  force  of  the  Observatory."  —  "  In  August 
I  had  some  correspondence  about  the  Egyptian  wooden 
astronomical  tablets  with  Mr  Gresswell  and  others  :  they 
were  fully  examined  by  Mr  Ellis.  —  In  this  year  I  was  much 
engaged  on  schemes  for  compasses,  and  in  June  I  sent  my 
Paper  on  Discussions  of  Ships'  Magnetism  to  the  Royal 
Society.  —  On  Dec.  6th  the  mast  of  the  Observatory  time-ball 
broke,  and  the  Ball  fell  in  the  Front  Court.  —  On  Aug.  4th 
my  valued  friend  Mr  Sheepshanks  died  ;  and  on  Aug.  I4th  I 
went  to  London  to  see  the  Standard  Bars  as  left  by  him. 
Afterwards,  on  Oct.  25th  I  went  to  Reading  to  collect  the 
papers  about  Standards  left  by  Mr  Sheepshanks.  —  I  made  a 
mechanical  construction  for  Euclid  I.  47,  with  which  I  was 
well  satisfied.  —  On  Apr.  I3th  I  joined  a  deputation  to  the 
Chancellor  of  the  Exchequer  (Sir  G.  Cornewall  Lewis)  on 
Decimal  Coinage." 

Of  private  history  :  "  I  was  at  Playford  for  a  large  part  of 


AT   GREENWICH   OBSERVATORY — 1846   TO    1856.        22$ 

January.— On  Mar.  26th  I  went  to  Reading,  to  visit  Mr 
Sheepshanks,  and  afterwards  to  Silchester  and  Hereford. — 
On  June  2ist  I  went  with  my  wife  and  two  eldest  sons  to 
Edinburgh  and  other  places  in  Scotland,  but  residing 
principally  at  Oban,  where  I  hired  a  house.  Amongst  other 
expeditions,  I  and  my  son  Wilfrid  went  with  the  *  Pharos ' 
(Northern  Lights  Steamer)  to  the  Skerry  Vohr  Lighthouse, 
&c.  I  also  visited  Newcastle,  &c.,  and  returned  to  Green- 
wich on  Aug.  2nd. — From  Oct.  I2th  to  I7th  I  was  at 
Cambridge. — On  Dec.  24th  I  went  to  Playford." 


A.  B.  15 


CHAPTER  VII. 

AT  GREENWICH  OBSERVATORY— 1856  TO  1866. 

1856 

"  IN  the  Report  to  the  Visitors  there  is  an  interesting 
account  of  the  difficulties  experienced  with  the  Reflex  Zenith 
Tube  in  consequence  of  the  tremors  of  the  quicksilver  trans- 
mitted through  the  ground.  Attempts  were  made  to  reduce 
the  tremor  by  supporting  the  quicksilver  trough  on  a  stage 
founded  at  a  depth  of  10  feet  below  the  surface,  but  it  was 
not  in  the  smallest  degree  diminished,  and  the  Report  states 
that  'The  experience  of  this  investigation  justifies  me  in 
believing  that  no  practicable  depth  of  trench  prevents  the 
propagation  of  tremor  when  the  soil  is  like  that  of  Greenwich 
Hill,  a  gravel,  in  all  places  very  hard,  and  in  some,  cemented 
to  the  consistency  of  rock.' — With  respect  to  the  regulation 
of  the  Post  Office  clocks,  '  One  of  the  galvanic  clocks  in  the 
Post  Office  Department,  Lombard  Street,  is  already  placed 
in  connection  with  the  Royal  Observatory,  and  is  regulated 
at  noon  every  day... other  clocks  at  the  General  Post  Office 
are  nearly  prepared  for  the  same  regulation,  and  I  expect 
that  the  complete  system  will  soon  be  in  action.' — Under  the 
head  of  General  Remarks  a  careful  summary  is  given  of  the 
work  of  the  Observatory,  and  the  paragraph  concludes  as 
follows :  '  Lastly  there  are  employments  which  connect  the 
scientific  Observatory  with  the  practical  world  ;  the  distribu- 
tion of  accurate  time,  the  improvement  of  marine  time- 


AT   GREENWICH   OBSERVATORY— 1856   TO    1 866.        22/ 

keepers,  the  observations  and  communications  which  tend  to 
the  advantage  of  Geography  and  Navigation,  and  the  study, 
in  a  practical  sense,  of  the  modifications  of  Magnetism ;  a 
careful  attention  to  these  is  likely  to  prove  useful  to  the 
world,  and  conducive  to  the  material  prosperity  of  the  Ob- 
servatory :  and  these  ought  not  to  be  banished  from  our 
system.' — In  September  I  prepared  the  first  specification  for 
the  building  to  carry  the  S.E.  Dome. — In  September,  learning 
that  Hansen's  Lunar  Tables  were  finished  in  manuscript,  I 
applied  to  Lord  Clarendon  and  they  were  conveyed  to  me 
through  the  Foreign  Office :  in  October  I  submitted  to  the 
Admiralty  the  proposal  for  printing  the  Tables,  and  in 
November  I  learned  that  the  Treasury  had  assented  to  the 
expense. — Lieut.  Daynou's  eclipses  and  occultations  for 
longitudes  of  points  in  South  Africa,  observed  in  1854  and 
1855,  were  calculated  here  in  this  year. — On  Feb.  i6th  I 
made  my  first  application  to  Sir  C.  Wood  (First  Lord  of  the 
Admiralty)  for  assistance  to  C.  Piazzi  Smyth  to  carry  out 
the  Teneriffe  Experiment :  grounding  it  in  part  on  the 
failure  of  attempts  to  see  the  solar  prominences.  He  gave 
encouragement,  and  on  Mar.  i8th  I  transmitted  Piazzi  Smyth's 
Memorial  to  the  Admiralty :  on  May  2nd  the  Admiralty 
authorized  an  expense  of  £500.  I  drew  up  suggestions. — 
The  Sheepshanks  Fund :  After  the  death  of  my  friend 
Richard  Sheepshanks,  his  sister  Miss  Anne  Sheepshanks 
wished  to  bestow  some  funds  in  connection  with  the  Uni- 
versity of  Cambridge,  Trinity  College,  and  Astronomy,  to 
which  his  name  should  be  attached.  There  must  have  been 
some  conversation  with  me,  but  the  first  letter  is  one  from 
De  Morgan  in  August.  In  September  I  had  a  conversation 
with  Miss  Sheepshanks,  and  sent  her  my  first  draft  of  a 
scheme,  to  which  she  assented.  On  Sept.  3Oth  I  wrote  to 
Whewell  (Master  of  Trinity)  who  was  much  trusted  by  Miss 
Sheepshanks :  he  consented  to  take  part,  and  made  some 
suggestions.  There  was  further  correspondence,  but  the 
business  did  not  get  into  shape  in  this  year. — In  connection 

J— 2 


228  GEORGE   BIDDELL  AIRY. 

with  the  Correction  of  the  Compass  in  Iron  Ships :  I  dis- 
cussed the  observations  made  in  the  voyage  of  the  Royal 
Charter.  On  Feb.  i^th  I  proposed  to  the  Admiralty  a 
system  of  mounting  the  compasses  with  adjustable  magnets, 
and  it  was  ordered  to  be  tried  in  the  Trident  and  Transit. — 
In  February  I  reported  to  the  Admiralty  that  the  Deal  Time- 
Ball  had  been  successful,  and  I  proposed  time-balls  at  Ports- 
mouth, Plymouth,  and  Sheerness.  There  was  much  corre- 
spondence in  various  directions  about  Portsmouth  and 
Devonport,  and  in  March  I  went  to  Devonport  and  specially 
examined  Mount  Wise  and  the  Devonport  Column. — I  had 
correspondence  with  Sir  Howard  Douglas  about  the  sea 
breaking  over  the  unfinished  Dover  Pier.  I  have  an  idea 
that  this  followed  evidence  given  by  me  to  a  Harbour  Com- 
mission, in  which  I  expressed  as  a  certainty  that  the  sea  will 
not  be  made  to  break  by  a  vertical  wall." 

Of  private  history :  "  I  returned  from  Playford  on  Jan. 
1 8th. — From  June  i6th  to  August  5th  I  was,  with  my  son 
Wilfrid,  on  an  expedition  to  South  Italy  and  Sicily :  on 
our  return  from  Sicily,  we  remained  for  three  days  ill  at 
Marseilles  from  a  touch  of  malaria. — On  Dec.  22nd  I  went  to 
Playford. — In  acknowledgment  of  the  pleasure  which  I  had 
derived  from  excursions  in  the  Cumberland  Passes,  I  made 
a  foot-bridge  over  a  troublesome  stream  on  the  Pass  of  the 
Sty  Head." 


1857 

"  In  the  Report  to  the  Visitors,  when  on  the  subject  of 
the  Altazimuth,  the  following  paragraph  occurs :  '  I  alluded 
in  a  preceding  section  to  the  cutting  away  of  a  very  small 
portion  of  one  of  the  rays  of  the  three-armed  pier  which 
carries  the  Altazimuth.  The  quality  of  the  brickwork  is 
the  best  that  I  have  ever  seen,  and  not  a  single  brick  was 
disturbed  beyond  those  actually  removed.  Yet  the  effect 
was  to  give  the  Altazimuth  an  inclination  of  about  25". 


AT   GREENWICH   OBSERVATORY — 1856  TO    1 866.        229 

This  inclination  evidently  depends  on  the  elasticity  of  the 
brickwork.' — With  reference  to  the  new  S.E.  Equatoreal  the 
Report  states  that  *  The  support  of  the  north  or  upper  end  of 
the  polar  axis  has  been  received,  and  is  planted  within  the 
walls  of  the  building  in  a  position  convenient  for  raising  it  to 
its  ultimate  destination.  It  is  one  piece  of  cast-iron,  and 
weighs  nearly  5  tons.' — Small  changes  as  previously  men- 
tioned had  been  noticed  with  regard  to  the  Zero  of  Azimuth 
of  the  Transit  Circle,  and  the  Report  states  that  *  In  regard 
to  the  Azimuth  of  the  Transit  Circle,  and  the  Azimuth  of  its 
Co-llimator,  Mr  Main  has  brought  together  the  results  of 
several  years,  and  the  following  law  appears  to  hold.  There 
is  a  well-marked  annual  periodical  change  in  the  position  of 
the  Transit  Circle,  the  southerly  movement  of  the  eastern 
pivot  having  its  minimum  value  in  September,  and  its  maxi- 
mum in  March,  the  extreme  range  being  about  14  seconds ; 
and  there  is  a  similar  change,  but  of  smaller  amount,  in  the 
position  of  the  Collimator.  I  cannot  conjecture  any  cause 
for  these  changes,  except  in  the  motion  of  the  ground. 
There  is  also  a  well-marked  connection  between  the  state  of 
level  of  the  axis  and  the  temperature.  The  eastern  pivot 
always  rises  when  the  temperature  rises,  the  extreme  range 
being  about  6  seconds.  I  cannot  offer  any  explanation  of 
this.' — Under  the  head  of  Extraneous  Works  the  Report 
states  that  '  The  British  Government  had  for  some  years  past 
contributed  by  pecuniary  grants  to  the  preparation  of  Prof. 
Hansen's  Lunar  Tables.  In  the  last  winter  they  undertook 
the  entire  expense  of  printing  a  large  impression  of  the 
Tables.  The  reading  of  the  proof-sheets  (a  very  considerable 
labour)  has  been  effected  entirely  at  the  Observatory.  I  may 
take  this  opportunity  of  stating  that  the  use  of  these  Tables 
has  enabled  me,  as  I  think,  incontestably  to  fix  the  capture 
of  Larissa  to  the  date  B.C.  557,  May  19.  This  identification 
promises  to  prove  valuable,  not  merely  for  its  chronological 
utility,  but  also  for  its  accurate  determination  of  an  astro- 
nomical epoch,  the  point  eclipsed  being  exactly  known,  and 


230  GEORGE   BIDDELL  AIRY. 

the  shadow  having  been  very  small.' — In  April  I  gave  a 
lecture  to  the  Royal  Astronomical  Society  on  the  methods 
available  through  the  next  25  years  for  the  determination  of 
the  Sun's  parallax. — Dr  Livingstone's  observations  for  African 
longitudes  were  computed  at  the  Observatory. — The  Ad- 
miralty enquire  of  me  about  the  feasibility  of  adopting 
Piazzi  Smyth's  construction  for  steadying  telescopes  on  board 
ship :  I  gave  a  Report,  of  mixed  character,  on  the  whole  dis- 
couraging.— I  had  correspondence  with  G.  P.  Bond  and  others 
about  photographing  the  Stars  and  Moon. — On  Feb.  i/th 
Piazzi  Smyth's  books,  &c.  relating  to  the  Teneriffe  Experi- 
ment were  sent  to  me :  I  recommended  that  an  abridged 
Report  should  be  sent  to  the  Royal  Society. — Respecting  the 
Sheepshanks  Fund :  there  was  correspondence  with  Miss 
Sheepshanks  and  Whewell,  but  nothing  got  into  shape  this 
year:  Miss  Sheepshanks  transferred  to  me  ^"10,000  lying  at 
Overend  and  Gurney's. — In  November  experiments  were 
made  for  the  longitude  of  Edinburgh,  which  failed  totally 
from  the  bad  state  of  the  telegraph  wire  between  Deptford 
and  the  Admiralty. — In  June  the  first  suggestion  was  made 
to  me  by  Capt.  Washington  for  time-signals  on  the  Lizard 
Point :  which  in  no  long  time  I  changed  for  the  Start  Point. 
— The  Admiralty  call  for  estimates  for  a  time-ball  at  Ports- 
mouth :  on  receiving  them  they  decline  further  proceeding. — 
I  was  engaged  in  speculations  and  correspondence  about  the 
Atlantic  Submarine  Cable. — In  the  Royal  Astronomical 
Society,  I  presented  Memoirs  and  gave  lectures  on  the  three 
great  chronological  eclipses  (Agathocles,  Thales,  Larissa)." — 
On  Dec.  5th  Airy  wrote  to  the  Vice-Chancellor  of  the  Uni- 
versity of  Cambridge,  objecting  to  the  proposed  changes 
regarding  the  Smith's  Prizes — a  subject  in  which  he  took 
much  interest,  and  to  which  he  ascribed  great  importance. — 
"  On  Apr.  27th  I  was  in  correspondence  with  G.  Herbert  of 
the  Trinity  House,  about  floating  beacons. — In  July  I  re- 
ported to  the  Treasury  on  the  Swedish  Calculating  Engine 
(I  think  on  the  occasion  of  Mr  Farr,  of  the  Registrar- 


AT   GREENWICH   OBSERVATORY— 1856  TO    1866.        231 

General's  Office,  applying  for  one). — In  November  I  had 
correspondence  about  the  launch  of  the  Great  Eastern,  and 
the  main  drainage  of  London." 

Of  private  history :  "  On  Jan.  I4th  I  returned  from  Play- 
ford. — From  June  2/th  to  Aug.  5th  I  was  travelling  in 
Scotland  with  my  wife  and  two  eldest  sons,  chiefly  in  the 
West  Highlands.  On  our  return  we  visited  Mrs  Smith  (my 
wife's  mother)  at  Brampton. — On  -Dec.  26th  I  went  to 
Playford." 


1858 

"  In  the  Minutes  of  the  Visitors  it  is  noted  that  the  new 
Queen's  Warrant  was  received.  The  principal  change  was  the 
exclusion  of  the  Astronomer  Royal  and  the  other  Observatory 
Officers  from  the  Board. — In  the  Report  to  the  Visitors  it  is 
stated  that  '  The  Papers  of  the  Board  of  Longitude  are  now 
finally  stitched  into  books.  They  will  probably  form  one  of 
the  most  curious  collections  of  the  results  of  scientific  enter- 
prise, both  normal  and  abnormal,  which  exists.' — It  appears 
that  the  galvanic  communications,  external  to  the  Observa- 
tory, had  been  in  a  bad  state,  the  four  wires  to  London 
Bridge  having  probably  been  injured  by  a  thunderstorm  in 
the  last  autumn,  and  the  Report  states  that  '  The  state  of  the 
wires  has  not  enabled  us  to  drop  the  Ball  at  Deal.  The 
feeble  current  which  arrives  there  has  been  used  for  some 
months  merely  as  giving  a  signal,  by  which  an  attendant  is 
guided  in  dropping  the  Ball  by  hand/ — Regarding  the  new 
Equatoreal  the  Report  states  that  'For  the  new  South-East 
Equatoreal,  the  object-glass  was  furnished  by  Messrs  Merz 
and  Son  in  the  summer  of  last  year,  and  I  made  various  trials 
of  it  in  a  temporary  tube  carried  by  the  temporary  mounting 
which  I  had  provided,  and  finally  I  was  well  satisfied  with  it. 
I  cannot  yet  say  that  I  have  certainly  divided  the  small  star 
of  7  Andromedae ;  but,  for  such  a  test,  a  combination  of 
favourable  circumstances  is  required.  From  what  I  have 


232  GEORGE   BIDDELL  AIRY. 

seen,  I  have  no  doubt  of  its  proving  a  first-rate  object-glass.' 
— On  March  I5th  was  an  annular  eclipse  of  the  Sun,  for  the 
observation  of  which  I  sent  parties  fully  equipped  to  Bedford, 
Wellingborough,  and  Market  Ha-fborough.     The  observations 
failed  totally  in  consequence  of  the  bad  weather :   I  myself 
went  to   Harrowden  near  Wellingborough. — Respecting  the 
Altazimuth,  the  Report  states  that  with  due  caution  as  to  the 
zero  of  azimuth  'the  results  of  observation  are   extremely 
good,  very  nearly  equal  to  those  of  the  meridional  instru- 
ment ;  perhaps  I  might  say  that  three  observations  with  the 
Altazimuth  are  equivalent  to  two  with  the  Transit  Circle.' — 
Respecting  Meteorological    Observations  the   Report   states 
that '  The  observations  of  the  maximum  and  minimum  ther- 
mometers in  the  Thames,  interrupted  at  the  date  of  the  last 
Report,  have  been   resumed,  and  are  most  regularly  main- 
tained.    Regarding  the  Thames  as  the  grand  climatic  agent 
on  London  and  its  neighbourhood,  I  should  much  regret  the 
suppression  of  these  observations.' — After  much  trouble  the 
longitude  of  Edinburgh  had  been  determined :  '  the  retard  of 
the  current  is  O'O4S  very  nearly,  and  the  difference  of  longi- 
tudes I2m  43'O5S,  subject  to  personal  equations.' — The  Report 
concludes  thus :  '  With  regard  to  the  direction  of  our  labours, 
I  trust  that  I  shall  always  be  supported  by  the  Visitors  in 
my  desire  to  maintain  the  fundamental  and  meridional  system 
of  the  Observatory  absolutely  intact.     This,  however,  does 
not  impede  the  extension  of  our  system  in  any  way  whatever, 
provided  that  such  means  are  arranged  for  carrying  out  the 
extension    as   will    render    unnecessary    the    withdrawal    of 
strength  from  what  are  now  the  engrossing  objects  of  the 
Observatory.' — I    had    much   correspondence  on  Comets,  of 
which  Donati's  great  Comet  was  one :  the  tail  of  this  Comet 
passed  over  Arcturus  on  October  5th. — Respecting  the  Sheep- 
shanks Fund :  In  September  I  met  Whewell  at  Leeds,  and 
we  settled  orally  the  final  plan  of  the  scheme.     On  Oct.  27th 
I  saw  Messrs  Sharp,  Miss  Sheepshanks's  solicitors,  and  drew 
up  a  Draft  of  the  Deed  of  Gift.     There  was  much  corre- 


AT   GREENWICH   OBSERVATORY — 1856  TO    1 866.         233 

spondence,  and  on  Nov.  2Oth  I  wrote  to  the  Vice-Chancellor 
of  Cambridge  University.  A  counter-scheme  was  proposed 
by  Dr  Philpott,  Master  of  St  Catharine's  College.  By  arrange- 
ment I  attended  the  Council  of  the  University  on  Dec.  3rd, 
and  explained  my  views,  to  which  the  Council  assented.  On 
Dec.  Qth  the  Senate  accepted  the  gift  of  Miss  Sheepshanks. — 
I  had  much  correspondence  throughout  this  year,  with  the 
Treasury,  Herschel,  Sabine,  and  the  Royal  Society,  about  the 
continuation  of  the  Magnetic  Establishments.  The  Reduc- 
tions of  the  Magnetic  Observations  1848-1857  were  com- 
menced in  February  of  this  year,  under  the  direction  of  Mr 
Lucas,  a  computer  who  had  been  engaged  on  the  Lunar 
Reductions. — In  this  year  I  came  to  a  final  agreement  with 
the  South  Eastern  Railway  Company  about  defining  the 
terms  of  our  connection  with  them  for  the  passage  of  Time 
Signals.  I  was  authorized  by  the  Admiralty  to  sign  the 
'protocol'  or  Memorandum  of  Agreement,  and  it  was  signed 
by  the  South  Eastern  Railway  Directors. — On  Aug.  28th  I 
made  my  first  proposal  to  Sir  John  Packington  (First  Lord 
of  the  Admiralty)  for  hourly  time  signals  on  the  Start  Point, 
and  in  September  I  went  to  the  Start  to  examine  localities, 
&c.  On  Dec.  23rd  the  Admiralty  declined  to  sanction  it. — I 
presented  to  the  Royal  Society  a  Paper  about  drawing  a 
great-circle  trace  on  a  Mercator's  chart. — In  October  I  gave 
a  Lecture  on  Astronomy  in  the  Assembly  Room  at  Bury. — 
On  Jan.  2 5th  I  was  busied  with  my  Mathematical  Tracts  for 
republication." — In  this  year  Airy  published  in  the  Athenaeum 
very  careful  and  critical  remarks  on  the  Commissioners'  Draft 
of  Statutes  for  Trinity  College.  He  was  always  ready  to  take 
action  in  the  interests  of  his  old  College.  This  Paper  pro- 
cured him  the  warmest  gratitude  from  the  Fellows  of  the 
College. 

Of  private  history :  "  On  Jan.  23rd  I  returned  from  Play- 
ford.  From  July  5th  to  Aug.  6th  I  was  on  an  expedition  in 
Switzerland  with  my  two  eldest  sons.  At  Paris  we  visited 
Le  Verrier,  and  at  Geneva  we  visited  Gautier,  De  La  Rive, 


234  GEORGE   BIDDELL  AIRY. 

and  Plantamour.  We  returned  by  Brussels. — On  Dec.  23rd  I 
went  to  Playford." — In  this  year  was  erected  in  Play  ford 
Churchyard  a  granite  obelisk  in  memory  of  Thomas  Clark- 
son.  It  was  built  by  subscription  amongst  a  few  friends  of 
Clarkson's,  and  the  negociations  and  arrangements  were 
chiefly  carried  out  by  Airy,  who  zealously  exerted  himself  in 
the  work  which  was  intended  to  honour  the  memory  of  his 
early  friend.  It  gave  him  much  trouble  during  the  years 
1856  to  1858. 

Here  is  a  letter  to  the  Editor  of  the  Athenaeum  on  some 
other  Trinity  matters: 


1858,  November  22. 
DEAR  SIR, 

In  the  Athenaeum  of  November  20,  page  650,  column  3, 
paragraph  4,  there  is  an  account  of  the  erection  of  the  statue  of 
Barrow  in  Trinity  College  Antechapel  (Cambridge)  conceived  in  a 
spirit  hostile  to  the  University,  and  written  in  great  ignorance  of  the 
facts.  On  the  latter  I  can  give  the  writer  some  information. 

The  Marquis  of  Lansdowne,  who  was  a  Trinity  man  and  whose 
son  was  of  Trinity,  intimated  to  the  authorities  of  the  College  that 
he  was  desirous  of  placing  in  the  antechapel  a  statue  of  Milton. 
This,  regard  being  had  to  the  customs  and  the  college-feelings  of 
Cambridge,  was  totally  impossible.  The  antechapel  of  every  college 
is  sacredly  reserved  for  memorials  of  the  men  of  that  college  only; 
and  Milton  was  of  Christ's  College.  The  Marquis  of  Lansdowne, 
on  hearing  this  objection,  left  the  choice  of  the  person  to  be  com- 
memorated, to  certain  persons  of  the  college,  one  of  whom  (a  literary 
character  of  the  highest  eminence  and  a  profound  admirer  of  Milton) 
has  not  resided  in  Cambridge  for  many  years.  Several  names  were 
carefully  considered,  and  particularly  one  (not  mentioned  by  your 
correspondent)  of  very  great  literary  celebrity,  but  in  whose  writings 
there  is  ingrained  so  much  of  ribaldry  and  licentiousness  that  he  was 
at  length  given  up.  Finally  the  choice  rested  on  Barrow,  not  as 
comparable  to  Milton,  but  as  a  person  of  reputation  in  his  day  and 
as  the  best  who  could  be  found  under  all  the  circumstances. 

Cromwell  never  was  mentioned  ;   he  was  a  member  of  Sidney 


AT   GREENWICH   OBSERVATORY — 1856  TO    1 866.        235 

College:  moreover  it  would  have  been  very  wrong  to  select  the 
exponent  of  an  extreme  political  party.  But  Cromwell  has  I  believe 
many  admirers  in  Cambridge,  to  which  list  I  attach  myself. 

I  had  no  part  in  the  negociations  above  mentioned,  but  I  saw 
the  original  letters,  and  I  answer  for  the  perfect  correctness  of  what 
I  have  stated.  But  as  I  am  not  a  principal,  I  decline  to  appear  in 
public. 

It  is  much  to  be  desired,  both  for  the  Athenaeum  and  for  the 
public,  that  such  an  erroneous  statement  should  not  remain  uncor- 
rected.  And  I  would  suggest  that  a  correction  by  the  Editor  would 
be  just  and  graceful,  and  would  tend  to  support  the  Athenaeum  in 
that  high  position  which  it  has  usually  maintained. 

I  am,  dear  Sir, 

Yours  very  faithfully, 

G.    B.    AIRY. 

Hepworth  Dixon,  Esq. 


1859 

"The  Report  to  the  Visitors  states  that  'The  Lunar 
Reductions  with  amended  elements  (especially  parallax)  for 
correction  of  Observations  from  1831  to  1851  are  now  com- 
pleted. It  is,  I  think,  matter  of  congratulation  to  the  Obser- 
vatory and  to  Astronomy,  that  there  are  now  exhibited  the 
results  of  uninterrupted  Lunar  Observations  extending  through 
more  than  a  century,  made  at  the  same  place,  reduced  under 
the  same  superintendence  and  on  the  same  general  principles, 
and  compared  throughout  with  the  same  theoretical  Tables.' 
— After  reference  to  the  great  value  of  the  Greenwich  Lunar 
Observations  to  Prof.  Hansen  in  constructing  his  Tables,  and 
to  the  liberality  of  the  British  Government  in  their  grants  to 
Hansen,  the  Report  continues  thus :  '  A  strict  comparison  of 
Hansen's  Tables  with  the  Greenwich  Observations  of  late 
years,  both  meridional  and  extra-meridional,  was  commenced. 
The  same  observations  had,  in  the  daily  routine  of  the  Obser- 
vatory, been  compared  with  the  Nautical  Almanac  or  Burck- 


236  GEORGE  BIDDELL  AIRY. 

hardt's  Tables.  The  result  for  one  year  only  (1852)  has  yet 
reached  me,  but  it  is  most  remarkable.  The  sum  of  squares 
of  residual  errors  with  Hansen's  Tables  is  only  one-eighth 
part  of  that  with  Burckhardt's  Cables.  When  it  is  remem- 
bered that  in  this  is  included  trie  entire  effect  of  errors  and 
irregularities  of  observation,  we  shall  be  justified  in  consider- 
ing Hansen's  Tables  as  nearly  perfect.  So  great  a  step,  to 
the  best  of  my  knowledge,  has  never  been  made  in  numerical 
physical  theory.  I  have  cited  this  at  length,  not  only  as 
interesting  to  the  Visitors  from  the  circumstance  that  we 
have  on  our  side  contributed  to  this  great  advance,  but  also 
because  an  innovation,  peculiar  to  this  Observatory,  has  in  no 
small  degree  aided  in  giving  a  decisive  character  to  the  com- 
parison. I  have  never  concealed  my  opinion  that  the  intro- 
duction and  vigorous  use  of  the  Altazimuth  for  observations 
of  the  Moon  is  the  most  important  addition  to  the  system  of 
the  Observatory  that  has  been  made  for  many  years.  The 
largest  errors  of  Burckhardt's  Tables  were  put  in  evidence 
almost  always  by  the  Altazimuth  Observations,  in  portions  of 
the  Moon's  Orbit  which  could  not  be  touched  by  the  meri- 
dional instruments ;  they  amounted  sometimes  to  nearly  40" 
of  arc,  and  they  naturally  became  the  crucial  errors  for  dis- 
tinction between  Burckhardt's  and  Hansen's  Tables.  Those 
errors  are  in  all  cases  corrected  with  great  accuracy  by  Han- 
sen's Tables.' — The  Report  concludes  with  the  following 
paragraph :  '  With  the  inauguration  of  the  new  Equatoreal 
will  terminate  the  entire  change  from  the  old  state  of  the 
Observatory.  There  is  not  now  a  single  person  employed  or 
instrument  used  in  the  Observatory  which  was  there  in  Mr 
Pond's  time,  nor  a  single  room  in  the  Observatory  which  is 
used  as  it  was  used  then.  In  every  step  of  change,  however, 
except  this  last,  the  ancient  and  traditional  responsibilities  of 
the  Observatory  have  been  most  carefully  considered :  and, 
in  the  last,  the  substitution  of  a  new  instrument  was  so  abso- 
lutely necessary,  and  the  importance  of  tolerating  no  instru- 
ment except  of  a  high  class  was  so  obvious,  that  no  other 


AT  GREENWICH   OBSERVATORY — 1856  TO    1 866.        237 

course  was  open  to  us.  I  can  only  trust  that,  while  the  use 
of  the  Equatoreal  within  legitimate  limits  may  enlarge  the 
utility  and  the  reputation  of  the  Observatory,  it  may  never 
be  permitted  to  interfere  with  that  which  has  always  been 
the  staple  and  standard  work  here.' — Concerning  the  Sheep- 
shanks Fund  :  There  was  much  correspondence  about  settling 
the  Gift  till  about  Feb.  2ist.  I  took  part  in  the  first  exami- 
nation for  the  Scholarship  in  October  of  this  year,  and  took 
my  place  with  the  Trinity  Seniority,  as  one  of  their  number 
on  this  foundation,  for  some  general  business  of  the  Fund. — 
With  respect  to  the  Correction  of  the  Compass  in  Iron  Ships : 
I  sent  Mr  Ellis  to  Liverpool  to  see  some  practice  there  in  the 
correction  of  the  Compass.  In  September  I  urged  Mr  Rundell 
to  make  a  voyage  in  the  Great  Eastern  (just  floated)  for 
examination  of  her  compasses,  and  lent  him  instruments : 
very  valuable  results  were  obtained.  Mr  Archibald  Smith 
had  edited  Scoresby's  Voyage  in  the  Royal  Charter,  with  an 
introduction  very  offensive  to  me :  I  replied  fully  in  the 
Athenaeum  of  Nov.  7th.— The  Sale  of  Gas  Act :  An  Act  of 
Parliament  promoted  by  private  members  of  the  House  of 
Commons  had  been  passed,  without  the  knowledge  or  recol- 
lection of  the  Government.  It  imposed  on  the  Government 
various  duties  about  the  preparation  of  Standards.  Suddenly, 
at  the  very  expiration  of  the  time  allowed  this  came  to  the 
knowledge  of  Government.  On  Oct.  ist  Lord  Monteagle 
applied  to  me  for  assistance.  On  Oct.  15th  and  22nd  I  wrote- 
to  Mr  Hamilton,  Secretary  of  the  Treasury,  and  received 
authority  to  ask  for  the  assistance  of  Prof.  W.  H.  Miller. — I 
made  an  examination  of  Mr  Ball's  eyes  (long-sighted  and 
short-sighted  I  think). — In  February  I  made  an  Analysis  of 
the  Cambridge  Tripos  Examination,  which  I  communicated 
to  some  Cambridge  residents,"  In  a  letter  on  this  subject  to 
one  of  his  Cambridge  friends  Airy  gives  his  opinion  as 
follows :  "  I  have  looked  very  carefully  over  the  Examination 
Papers,  and  think  them  on  the  whole  very  bad.  They  are 
utterly  perverted  by  the  insane  love  of  Problems,  and  by  the 


238  GEORGE   BIDDELL  AIRY. 

foolish  importance  given  to  wholly  useless  parts  of  Alge- 
braical Geometry.  For  the  sake  of  these,  every  Physical 
Subject  and  every  useful  application  of  pure  mathematics  are 
cut  down  or  not  mentioned."  T?his  led  to  much  discussion  at 
Cambridge.  In  this  year  the  Smith's  Prizes  were  awarded  to 
the  4th  and  6th  Wranglers. 

Of  private  history :  "  On  Apr.  29th  Mrs  Smith  (my  wife's 
mother)  died  at  Brampton. — From  July  4th  to  Aug.  2nd  I 
was  in  France  (Auvergne  and  the  Vivarais)  with  my  two 
eldest  sons.  Maclear  travelled  with  us  to  Paris. — On  Dec. 
23rd  I  went  to  Playford." — Antiquities  and  historical  ques- 
tions connected  with  military  movements  had  a  very  great 
attraction  for  Airy.  On  his  return  from  the  expedition  in 
France  above-mentioned,  he  engaged  in  considerable  corre- 
spondence with  military  authorities  regarding  points  con- 
nected with  the  battle  of  Toulouse.  And  in  this  year  also 
he  had  much  correspondence  with  the  Duke  of  Northumber- 
land concerning  his  Map  of  the  Roman  Wall,  and  the  military 
points  relating  to  the  same. 

1860 

"  In  June  Mr  Main  accepted  the  office  of  Radcliffe  Observer 
at  Oxford  (Mr  Johnson  having  died)  and  resigned  the  First 
Assistancy  at  Greenwich :  in  October  Mr  Stone  was  appointed 
First  Assistant. — At  an  adjourned  Meeting  of  the  Visitors  on 
June  1 8th  there  were  very  heavy  discussions  on  Hansen's 
merits,  and  about  the  grant  to  him.  Papers  were  read  from 
Sir  J.  Lubbock,  Babbage,  South,  Whewell,  and  me.  Finally 
it  was  recommended  to  the  Government  to  grant  ;£iooo  to 
Hansen,  which  was  paid  to  him. — In  the  Report  to  the  Board 
of  Visitors  the  following  remark  occurs :  *  The  apparent  exist- 
ence of  a  discordance  between  the  results  of  Direct  Observa- 
tions and  Reflection  Observations  (after  the  application  of 
corrections  for  flexure,  founded  upon  observations  of  the 
horizontal  collimator  wires)  to  an  extent  far  greater  than  can 


AT  GREENWICH   OBSERVATORY — 1856  TO    1 866.        239 


be  explained  by  any  disturbance  of  the  direction  of  gravity 
on  the  quicksilver  by  its  distance  from  the  vertical,  or  by  the 
attraction  of  neighbouring  masses,  perplexes  me  much.' — 
With  respect  to  the  discordance  of  dips  of  the  dipping-needles, 
which  for  years  past  had  been  a  source  of  great  trouble  and 
puzzle,  the  Report  states  that  ( The  dipping-needles  are  still  a 
source  of  anxiety.  The  form  which  their  anomalies  appear 
to  take  is  that  of  a  special  or  peculiar  value  of  the  dip  given 
by  each  separate  needle.  With  one  of  the  9-inch  needles, 
the  result  always  differs  about  a  quarter  of  a  degree  from  that 
of  the  others.  I  can  see  nothing  in  its  mechanical  construc- 
tion to  explain  this. — Reference  is  made  to  the  spontaneous 
currents  through  the  wires  of  telegraph  companies,  which  are 
frequently  violent  and  always  occur  at  the  times  of  magnetic 
storms,  and  the  Report  continues  '  It  may  be  worth  consider- 
ing whether  it  would  ever  be  desirable  to  establish  in  two 
directions  at  right  angles  to  each  other  (for  instance,  along 
the  Brighton  Railway  and  along  the  North  Kent  Railway) 
wires  which  would  photographically  register  in  the  Royal 
Observatory  the  currents  that  pass  in  these  directions,  exhi- 
biting their  indications  by  photographic  curves  in  close  juxta- 
position with  the  registers  of  the  magnetic  elements.' — In 
connection  with  the  Reduction  of  the  Greenwich  Lunar 
Observations  from  1831  to  1851,  the  Report  states  that  'The 
comparison  of  Hansen's  Lunar  Tables  with  the  Greenwich 
Observations,  which  at  the  last  Visitation  had  been  completed 
for  one  year  only,  has  now  been  finished  for  the  twelve  years 
1847  to  ^58.  The  results  for  the  whole  period  agree  entirely, 
in  their  general  spirit,  with  those  for  the  year  1852  cited  in 
the  last  Report.  The  greatest  difference  between  the  merits 
of  Burckhardt's  and  Hansen's  Tables  appears  in  the  Meri- 
dional Longitudes  1855,  when  the  proportion  of  the  sum  of 
squares  of  errors  is  as  31  (Burckhardt)  to  2  (Hansen).  The 
nearest  approach  is  in  the  Altazimuth  Latitudes  1854,  when 
the  proportion  of  the  sum  of  squares  of  errors  is  as  12 
(Burckhardt)  to  5  (Hansen).'— A  special  Address  to  the  Mem- 


240  GEORGE   BIDDELL  AIRY. 

bers  of  the  Board  of  Visitors  has  reference  to  the  proposals  of 
M.  Struve  for  (amongst  other  matters)  the  improved  deter- 
mination of  the  longitude  of  Valencia,  and  the  galvanic  deter- 
mination of  the  extreme  Eastern  Station  of  the  British 
triangles. — On  Sept.  I3th  I  circulated  amongst  the  Visitors 
my  Remarks  on  a  Paper  entitled  '  On  the  Polar  Distances  of 
the  Greenwich  Transit-Circle,  by  A.  Marth,' '"printed  in  the 
Astronomische  Nachrichten ;  the  Paper  by  Mr  Marth  was  an 
elaborate  attack  on  the  Greenwich  methods  of  observation, 
and  my  Remarks  were  a  detailed  refutation  of  his  statements. 
— On  Oct.  2Oth  I  made  enquiry  of  Sabine  as  to  the  advan- 
tage of  keeping  up  magnetic  observations.  On  Oct.  22nd  he 
wrote,  avoiding  my  question  in  some  measure,  but  saying 
that  our  instruments  must  be  changed  for  such  as  those  at 
Kew  (his  observatory) :  I  replied,  generally  declining  to  act 
on  that  advice. — In  March  and  April  I  was  in  correspondence 
with  Mr  Cowper  (First  Commissioner  of  Works,  &c.)  about 
the  bells  of  the  Westminster  Clock ;  also  about  the  smoky 
chimneys  of  the  various  apartments  of  the  Palace.  On  Apr. 
2  ist  I  made  my  Report  on  the  clock  and  bells,  20  foolscap 
pages.  I  employed  a  professional  musician  to  examine  the 
tones  of  the  bells. — In  November  I  was  writing  my  book  on 
Probable  Errors,  &c. — I  was  engaged  on  the  Tides  of  Kurra- 
chee  and  Bombay. — The  first  examination  of  Navy  telescopes 
was  made  for  the  Admiralty. — Hoch's  Paper  on  Aberration 
appeared  in  the  Astronomische  Nachrichten.  This  (with 
others)  led  to  the  construction  of  the  water-telescope  several 
years  later. — In  September  I  wrote  in  the  Athenaeum  against 
a  notion  of  Sir  H.  James  on  the  effect  of  an  upheaval  of  a 
mountain  in  changing  the  Earth's  axis.  In  October  I  had 
drawn  up  a  list  of  days  for  a  possible  evagation  of  the  Earth's 
poles  :  but  apparently  nothing  was  done  upon  them. 

"  In  this  year  I  was  a  good  deal  occupied  for  the  Light- 
house Commission.  On  Feb.  2ist  Admiral  Hamilton  (chair- 
man) applied  to  me  for  assistance.  In  April  I  went  to 
Chance's  Factory  in  Birmingham  on  this  business.  In  May 


AT   GREENWICH   OBSERVATORY— 1856   TO    1 866.        24! 

I  made  my  report  on  the  Start  Lighthouse,  after  inspection 
with  the  Commission.  In  June,  with  my  son  Hubert,  I 
visited  the  Whitby  Lighthouses,  and  discovered  a  fault  of  a 
singular  kind  which  most  materially  diminished  their  power. 
This  discovery  led  to  a  general  examination  of  lighthouses 
by  the  Trinity  Board,  to  a  modification  of  many,  and  to  a 
general  improvement  of  system.  On  June  25th  I  reported 
on  the  Lights  at  Calais,  Cap  de  Valde,  Grisnez,  South  Fore- 
land, and  North  Foreland.  In  August  I  had  been  to  the 
North  Foreland  again,  and  in  September  to  Calais  and  the 
Cap  d'Ailly.  In  October  I  went  with  my  son  Hubert  to 
Aberdeen  to  see  the  Girdleness  Lighthouse.  On  Nov.  loth 
I  made  a  General  Report. 

"  This  was  the  year  of  the  great  total  solar  eclipse  visible 
in  Spain.  At  my  representation,  the  Admiralty  placed  at 
my  command  the  large  steamship  '  Himalaya '  to  carry  about 
60  astronomers,  British  and  Foreign.  Some  were  landed  at 
Santander :  I  with  many  at  Bilbao.  The  Eclipse  was  fairly 
well  observed  :  1  personally  did  not  do  my  part  well.  The 
most  important  were  Mr  De  La  Rue's  photographic  opera- 
tions. At  Greenwich  I  had  arranged  a  very  careful  series  of 
observations  with  the  Great  Equatoreal,  which  were  fully 
carried  out." 

The  eclipse  expedition  to  Spain,  shortly  referred  to 
above,  was  most  interesting,  not  merely  from  the  importance 
of  the  results  obtained  (and  some  of  the  parties  were  very 
fortunate  in  the  weather)  but  from  the  character  of  the  expe- 
dition. It  was  a  wonderful  combination  of  the  astronomers 
of  Europe,  who  were  all  received  on  board  the  '  Himalaya,' 
and  were  conveyed  together  to  the  coast  of  Spain.  The 
polyglot  of  languages  was  most  remarkable,  but  the  utmost 
harmony  and  enthusiasm  prevailed  from  first  to  last,  and  this 
had  much  to  do  with  the  general  success  of  the  expedition. 
Those  who  landed  at  Bilbao  were  received  in  the  kindest  and 
most  hospitable  manner  by  Mr  C.  B.  Vignoles,  the  engineer- 
in-chief  of  the  Bilbao  and  Tudela  Railway,  which  was  then 
A.  B.  16 


242  GEORGE   BIDDELL   AIRY. 

under  construction.  This  gentleman  made  arrangements  for 
the  conveyance  of  parties  to  points  in  the  interior  of  the 
country  which  were  judged  suitable  for  the  observation  of  the 
eclipse,  and  placed  all  the  resources  of  his  staff  at  the  disposal 
of  the  expedition  in  the  most  liberal  manner.  The  universal 
opinion  was  that  very  great  difficulty  would  have  been  expe- 
rienced without  the  active  and  generous  assistance  of  Mr 
Vignoles.  It  is  needless  to  say  that  the  vote  of  thanks  to 
Mr  Vignoles,  proposed  by  the  Astronomer  Royal  during  the 
return  voyage,  was  passed  by  acclamation  and  with  a  very 
sincere  feeling  of  gratitude :  it  was  to  the  effect  that  '  without 
the  great  and  liberal  aid  of  Mr  C.  B.  Vignoles,  and  the  dis- 
interested love  of  science  evinced  by  him  on  this  occasion, 
the  success  of  the  "Himalaya"  eclipse  expedition  could  not 
have  been  ensured.'  There  is  a  graphic  and  interesting 
account  of  the  reception  of  the  party  at  Bilbao  given  in  the 
'Life  of  C.  B.  Vignoles,  F.R.S.,  Soldier  and  Civil  Engineer/ 
by  O.  J.  Vignoles,  M.A. 

Of  private  history :  "  On  May  26th  my  venerable  friend 
Arthur  Biddell  died.  He  had  been  in  many  respects  more 
than  a  father  to  me  :  I  cannot  express  how  much  I  owed  to 
him,  especially  in  my  youth. — From  June  I2th  to  i$th  I 
visited  the  Whitby  Lighthouses  with  my  son  Hubert. — From 
July  6th  to  28th  I  was  in  Spain,  on  the  '  Himalaya'  expedi- 
tion, to  observe  the  total  eclipse :  I  was  accompanied  by  my 
wife,  my  eldest  son,  and  my  eldest  daughter. — From  Oct.  5th 
to  1 8th  I  went  with  my  son  Hubert  to  Aberdeen  to  see  the 
Girdleness  Lighthouse,  making  lateral  trips  to  Cumberland 
in  going  and  returning. — On  Dec.  2ist  I  went  to  Playford." 


1861 

"  In  the  Report  to  the  Visitors  there  is  great  complaint  of 
want  of  room.  '  With  increase  of  computations,  we  want 
more  room  for  computers  ;  with  our  greatly  increased  busi- 
ness of  Chronometers  and  Time-Distribution,  we  are  in  want 


AT   GREENWICH   OBSERVATORY — 1856   TO    1 866.       243 

of  a  nearly  separate  series  of  rooms  for  the  Time-Depart- 
ment :  we  want  rooms  for  book-stores ;  and  we  require  rooms 
for  the  photographic  operations  and  the  computations  of  the 
Magnetic  Department.' — The  Report  gives  a  curious  history 
of  Dr  Bradley 's  Observations,  which  in  1776  had  been  trans- 
ferred to  the  University  of  Oxford,  and  proceeds  thus: 
1  More  lately,  I  applied  (in  the  first  instance  through  Lord 
Wrottesley)  to  the  Vice-Chancellor,  Dr  Jeune,  in  reference  to 
the  possibility  of  transferring  these  manuscripts  to  the  Royal 
Observatory.... Finally,  a  decree  for  the  transfer  of  the  manu- 
script observations  to  the  Royal  Observatory,  without  any 
condition,  was  proposed  to  Convocation  on  May  2nd,  and 
was  passed  unanimously.  And  on  May  7th  my  Assistant, 
Mr  Dunkin,  was  sent  to  Oxford  to  receive  them.  And  thus, 
after  a  delay  of  very  nearly  a  century,  the  great  work  of 
justice  is  at  length  completed,  and  the  great  gap  in  our 
manuscript  observations  is  at  length  filled  up/ — With  ref- 
erence to  the  Transit  Circle,  it  had  been  remarked  that  the 
Collimators  were  slightly  disturbed  by  the  proximity  of  the 
gas-flames  of  their  illuminators,  and  after  various  experi- 
ments as  to  the  cause  of  it,  the  Report  proceeds  thus :  *  To 
my  great  surprise,  I  found  that  the  disturbance  was  entirely 
due  to  the  radiation  of  the  flame  upon  a  very  small  corner 
(about  1 6  square  inches)  of  the  large  and  massive  stone  on 
which  the  collimator  is  planted.  The  tin  plates  were  subse- 
quently shaped  in  such  a  manner  as  to  protect  the  stone  as 
well  as  the  metal ;  and  the  disturbance  has  entirely  ceased.' — 
Regarding  the  large  S.E.  Equatoreal,  the  Report  states  that 
*  On  the  character  of  its  object-glass  I  am  now  able  to  speak, 
first,  from  the  examination  of  Mr  Otto  Struve,  made  in  a 
favourable  state  of  atmosphere ;  secondly,  from  the  examina- 
tions of  my  Assistants  (I  have  not  myself  obtained  a  sight  of 
a  test-object  on  a  night  of  very  good  definition).  It  appears 
to  be  of  the  highest  order.  The  small  star  of  y  Andromedae 
is  so  far  separated  as  to  shew  a  broad  dark  space  between  its 
components.  Some  blue  colour  is  shewn  about  the  bright 

16 — 2 


244  GEORGE   BIDDELL  AIRY. 

planets.'— It  is  noted  in  the  Report  that  'The  Equatoreal 
observations  of  the  Solar  Eclipse  are  completely  reduced ; 
and  the  results  are  valuable.  It  appears  from  them  that  the 
error  in  right  ascension  of  Burckhardt's  Lunar  Tables  at  the 
time  of  the  eclipse  amounted  to  about  38" ;  while  that  of 
Hansen's  (ultimately  adopted  by  Mr  Hind  for.  the  calculation 
of  the  eclipse)  did  not  exceed  3".' — With  regard  to  Chrono- 
meters it  is  stated  that  *  By  use  of  the  Chronometer  Oven,  to 
which  I  have  formerly  alluded,  we  have  been  able  to  give 
great  attention  to  the  compensation.  I  have  reason  to  think 
that  we  are  producing  a  most  beneficial  effect  on  the  manu- 
facture and  adjustment  of  chronometers  in  general.' — With 
regard  to  the  Cape  of  Good  Hope  Observatory  and  Survey, 
the  Admiralty  enquire  of  me  when  the  Survey  work  will  be 
completed,  and  I  enquire  of  Maclear  '  How  is  the  printing  of 
your  Survey  Work?'  In  1862  I  began  to  press  it  strongly, 
and  in  1863  very  strongly. —  I  introduced  a  method  (constantly 
pursued  since  that  time  at  the  Royal  Observatory)  for  com- 
puting interpolations  without  changes  of  sign. —  I  had  cor- 
respondence with  Herschel  and  Faraday,  on  the  possible 
effect  of  the  Sun's  radiant  heat  on  the  sea,  as  explaining  the 
curve  of  diurnal  magnetic  inequality.  (That  diurnal  in- 
equality was  inferred  from  the  magnetic  reductions  1848 — 
1857,  which  were  terminated  in  1860.) — Regarding  the  pro- 
posal of  hourly  time-signals  on  the  Start  Point,  I  consulted 
telegraph  engineers  upon  the  practical  points,  and  on  Dec. 
2  ist  I  proposed  a  formal  scheme,  in  complete  detail.  (The 
matter  has  been  repeatedly  brought  before  the  Admiralty,  but 
has  been  uniformly  rejected.) — I  was  engaged  on  the  question 
of  the  bad  ocular  vision  of  two  or  three  persons. — The  British 
Association  Meeting  was  held  at  Manchester:  I  was  President 
of  Section  A.  I  gave  a  Lecture  on  the  Eclipse  of  1860  to  an 
enormous  attendance  in  the  Free  Trade  Hall."  The  following 
record  of  the  Lecture  is  extracted  from  Dr  E.  J.  Routh's 
Obituary  Notice  of  Airy  written  for  the  Proceedings  of  the 
Royal  Society.  "  At  the  meeting  of  the  British  Association 


AT  GREENWICH   OBSERVATORY— 1856   TO    1866.        245 

at  Manchester  in  1861,  Mr  Airy  delivered  a  Lecture  on  the 
Solar  Eclipse  of  1860  to  an  assembly  of  perhaps  3000 
persons.  The  writer  remembers  the  great  Free  Trade  Hall 
crowded  to  excess  with  an  immense  audience  whose  attention 
and  interest,  notwithstanding  a  weak  voice,  he  was  able  to 
retain  to  the  very  end  of  the  lecture.... The  charm  of  Pro- 
fessor Airy's  lectures  lay  in  the  clearness  of  his  explanations. 
The  subjects  also  of  his  lectures  were  generally  those  to 
which  his  attention  had  been  turned  by  other  causes,  so  that 
he  had  much  that  was  new  to  tell.  His  manner  was  slightly 
hesitating,  and  he  used  frequent  repetitions,  which  perhaps 
were  necessary  from  the  newness  of  the  ideas.  As  the 
lecturer  proceeded,  his  hearers  forgot  these  imperfections  and 
found  their  whole  attention  rivetted  to  the  subject  matter." 

Of  private  history :  "  On  Jan.  2nd  there  was  a  most  re- 
markable crystallization  of  the  ice  on  the  flooded  meadows 
at  Playford :  the  frost  was  very  severe. — From  June  2Oth  to 
Aug.  1st  I  was  at  the  Grange  near  Keswick  (where  I  hired  a 
house)  with  my  wife  and  most  of  my  family. — From  Nov.  5th 
to  I4th  I  was  on  an  expedition  in  the  South  of  Scotland 
with  my  son  Wilfrid  :  we  walked  with  our  knapsacks  by  the 
Roman  Road  across  the  Cheviots  to  Jedburgh. — On  Dec. 
2  ist  I  went  to  Playford." 


1862 

"  The  Report  to  the  Board  of  Visitors  states  that  '  A  new 
range  of  wooden  buildings  (the  Magnetic  Offices)  is  in  pro- 
gress at  the  S.S.E.  extremity  of  the  Magnetic  Ground.  It  will 
include  seven  rooms.' — Also  '  I  took  this  opportunity  (the 
relaying  of  the  water-main)  of  establishing  two  powerful  fire- 
plugs (one  in  the  Front  Court,  and  one  in  the  Magnetic 
Ground);  a  stock  of  fire-hose  adapted  to  the  "Brigade-Screw" 
having  been  previously  secured  in  the  Observatory.' — 'Two 
wires,  intended  for  the  examination  of  spontaneous  earth- 
currents,  have  been  carried  from  the  Magnetic  Observatory 


246  GEORGE   BIDDELL  AIRY. 

to  the  Railway  Station  in  the  town  of  Greenwich.  From 
this  point  one  wire  is  to  be  led  to  a  point  in  the  neighbour- 
hood of  Croydon,  the  other  to  a  point  in  the  neighbourhood 
of  Dartford.  Each  wird  is  to  /be  connected  at  its  two  ex- 
tremities with  the  Earth.  The  angle  included  between  the 
general  directions  of  these  two  lines  is  nearly  a  right  angle.' 
— 'The  Kew  unifilar  magnetometer,  adapted  to  the  deter- 
mination of  the  horizontal  part  of  terrestrial  magnetic  force 
in  absolute  measure,  was  mounted  in  the  summer  of  1861  ; 
and  till  1862  February,  occasional  observations  (14  in  all) 
were  taken  simultaneously  with  the  old  and  with  the  new 
instrument.  The  comparison  of  results  shewed  a  steady  but 
very  small  difference,  not  greater  probably  than  may  cor- 
respond to  the  omission  of  the  inverse  seventh  powers  of 
distance  in  the  theoretical  investigation  ;  proving  that  the  old 
instrument  had  been  quite  efficient  for  its  purpose.' — Great 
efforts  had  been  made  to  deduce  a  law  from  the  Diurnal 
Inequalities  in  Declination  and  Horizontal  Force,  as  shewn 
by  the  Magnetic  observations ;  but  without  success :  the 
Report  states  that  'The  results  are  most  amazing,  for  the 
variation  in  magnitude  as  well  as  in  law.  What  cosmical 
change  can  be  indicated  by  them  is  entirely  beyond  my 
power  of  conjecture.' — *  I  have  alluded,  in  the  two  last  Re- 
ports, to  the  steps  necessary,  on  the  English  side,  for  com- 
pleting the  great  Arc  of  Parallel  from  Valencia  to  the  Volga. 
The  Russian  portion  of  the  work  is  far  advanced,  and  will  be 
finished  (it  is  understood)  in  the  coming  summer.  It  ap- 
peared to  me  therefore  that  the  repetition  of  the  measure  of 
astronomical  longitude  between  Greenwich  and  Valencia  could 
be  no  longer  delayed.  Two  Assistants  of  the  Royal  Obser- 
vatory (Mr  Dunkin  and  Mr  Criswick)  will  at  once  proceed  to 
Valencia,  for  the  determination  of  local  time  and  the  manage- 
ment of  galvanic  signals.' — '  I  now  ask  leave  to  press  the  sub- 
ject of  Hourly  Time  Signals  at  the  Start  Point  on  the  atten- 
tion of  the  Board,  and  to  submit  the  advantage  of  their 
addressing  the  Board  of  Admiralty  upon  it.  The  great 


AT   GREENWICH   OBSERVATORY — 1856  TO    1 866.       247 

majority  of  outward-bound  ships  pass  within  sight  of  the 
Start,  and,  if  an  hourly  signal  were  exhibited,  would  have  the 
means  of  regulating  their  chronometers  at  a  most  critical 
part  of  their  voyage.  The  plan  of  the  entire  system  of  opera- 
tions is  completely  arranged.  The  estimated  expense  of 
outfit  is  £2017,  and  the  estimated  annual  expense  is  £326 ; 
both  liable  to  some  uncertainty,  but  sufficiently  exact  to 
shew  that  the  outlay  is  inconsiderable  in  comparison  with 
the  advantages  which  might  be  expected  from  it.  I  know 
no  direction  of  the  powers  of  the  Observatory  which  would 
tend  so  energetically  to  carry  out  the  great  object  of  its 
establishment,  viz.  "the  finding  out  the  so  much  desired 
Longitude  at  Sea." ' — The  attention  of  the  Visitors  is  strongly 
drawn  to  the  pressure  on  the  strength  of  the  Observatory 
caused  by  the  observation  of  the  numerous  small  planets,  and 
the  paragraph  concludes  thus:  'I  shall,  however,  again  en- 
deavour to  effect  a  partition  of  this  labour  with  some  other 
Observatory.' — A  small  fire  having  occurred  in  the  Magnetic 
Observatory,  a  new  building  of  zinc,  for  the  operation  of 
naphthalizing  the  illuminating  gas,  is  in  preparation,  external 
to  the  Observatory :  and  thus  one  of  the  possible  sources  of 
accidental  fire  will  be  removed. — Miss  Sheepshanks  added, 
through  me,  £2000  to  her  former  gift:  I  transferred  it,  i 
believe,  to  the  Master  and  Seniors  of  Trinity  College." — In 
this  year  Airy  contributed  to  the  Royal  Society  two  Papers, 
one  "  On  the  Magnetic  properties  of  Hot-Rolled  and  Cold- 
Rolled  Malleable  Iron,"  the  other  "On  the  Strains  in  the 
Interior  of  Beams."  He  gave  evidence  before  the  Select 
Committee  on  Weights  and  Measures,  and  also  before  the 
Public  Schools  Commission. 

In  the  latter  part  of  1862  a  difference  arose  between  Airy 
and  Major-General  Sabine,  in  consequence  of  remarks  made 
by  the  latter  at  a  meeting  of  the  Committee  of  Recommen- 
dations of  the  British  Association.  These  remarks  were  to 
the  effect  "That  it  is  necessary  to  maintain  the  complete 
system  of  self-registration  of  magnetic  phaenomena  at  the 


248  GEORGE   BIDDELL  AIRY. 

Kew  Observatory,  because  no  sufficient  system  of  magnetic 
record  is  maintained  elsewhere  in  England " ;  implying 
pointedly  that  the  system  at  the  Royal  Observatory  of 
Greenwich  was  insufficient.  Ttyis  matter  was  taken  up  very 
warmly  by  Airy,  and  after  a  short  and  acrimonious  cor- 
respondence with  Sabine,  he  issued  a  private  Address  to  the 
Visitors,  enclosing  copies  of  the  correspondence  with  his 
remarks,  and  requesting  the  Board  to  take  the  matter  of  this 
attack  into  their  careful  consideration.  This  Address  is 
dated  November  1862,  and  it  was  followed  by  another  dated 
January  1863,  which  contains  a  careful  reply  to  the  various 
points  of  General  Sabine's  attack,  and  concludes  with  a 
distinct  statement  that  he  (the  Astronomer  Royal)  can  no 
longer  act  in  confidence  with  Sabine  as  a  Member  of  the 
Board  of  Visitors. 

Of  private  history :  There  were  the  usual  short  visits  to 
Playford  at  the  beginning  and  end  of  the  year. — From  June 
28th  to  Aug.  5th  he  was  in  Scotland  (chiefly  in  the  Western 
Highlands)  with  his  wife  and  his  sons  Hubert  and  Osmund.  In 
the  course  of  this  journey  he  visited  the  Corryvreckan  whirl- 
pool near  the  island  of  Scarba,  and  the  following  paragraph 
relating  to  this  expedition  is  extracted  from  his  journal : 
"Landed  in  Black  Mile  Bay,  island  of  Luing,  at  10.30.  Here 
by  previous  arrangement  with  Mr  A.  Brown,  agent  of  the 
steam-boat  company,  a  4-oared  boat  was  waiting  to  take  us 
to  Scarba  and  the  Corryvreckan.  We  were  pulled  across  to 
the  island  of  Lunga,  and  rowed  along  its  length,  till  we  came 
to  the  first  channel  opening  from  the  main  sea,  which  the 
sailors  called  the  Little  Gulf.  Here  the  sea  was  rushing 
inwards  in  a  manner  of  which  I  had  no  conception.  Streams 
were  running  with  raving  speed,  sometimes  in  opposite  direc- 
tions side  by  side,  with  high  broken-headed  billows.  Where 
the  streams  touched  were  sometimes  great  whirls  (one  not 
many  yards  from  our  boat)  that  looked  as  if  they  would  suck 
anything  down.  Sometimes  among  all  this  were  great  smooth 
parts  of  the  sea,  still  in  a  whirling  trouble,  which  were  sur- 


AT  GREENWICH   OBSERVATORY— 1856  TO    1 866.       249 

rounded  by  the  mad  currents.    We  seemed  entirely  powerless 
among  all  these." 

In  the  beginning  of  this  year  (1862)  the  Duke  of  Man- 
chester, in  writing  to  the  Rev.  W.  Airy,  had  said,  "  I  wish 
your  brother,  the  Astronomer  Royal,  could  be  induced  to 
have  investigations  made  as  to  whether  the  aspects  of  the 
Planets  have  any  effect  on  the  weather."  This  enquiry  pro- 
duced the  following  reply : 

A  subject  like  that  of  the  occult  influences  of  the  planets  (using 
the  word  occult  in  no  bad  sense  but  simply  as  meaning  not 
thoroughly  traced)  can  be  approached  in  two  ways — either  by  the 
a  priori  probability  of  the  existence  of  such  influences,  or  by  the  a 
posteriori  evidence  of  their  effects.  If  the  two  can  be  combined, 
the  subject  may  be  considered  as  claiming  the  dignity  of  a  science. 
Even  if  the  effects  alone  are  certain,  it  may  be  considered  that  we 
have  a  science  of  inferior  degree,  wanting  however  that  definiteness  of 
law  and  that  general  plausibility  which  can  only  be  given  when  true 
causes,  in  accordance  with  antecedent  experience  in  other  cases,  can 
be  suggested. 

Now  in  regard  to  the  a  priori  probability  of  the  existence  of 
planetary  influences,  I  am  far  from  saying  that  such  a  thing  is  im- 
possible. The  discoveries  of  modern  philosophy  have  all  tended  to 
shew  that  there  may  be  many  things  about  us,  unknown  even  to  the 
scientific  world,  but  which  well-followed  accidents  reveal  with  the 
most  positive  certainty.  It  is  known  that  every  beam  of  light  is 
accompanied  by  a  beam  of  chemical  agency,  totally  undiscoverable 
to  the  senses  of  light  or  warmth,  but  admitting  of  separation  from 
the  luminous  and  warm  rays;  and  producing  photogenic  effects. 
We  know  that  there  are  disturbances  of  magnetism  going  on  about 
us,  affecting  whole  continents  at  a  time,  unknown  to  men  in  general, 
but  traceable  with  facility  and  certainty,  and  which  doubtless  affect 
even  our  brains  and  nerves  (which  are  indisputably  subject  to  the 
influence  of  magnetism). 

Now  in  the  face  of  these  things  I  will  not  undertake  to  say  that 
there  is  any  impossibility,  or  even  any  want  of  plausibility  in  the 
supposition  that  bodies  external  to  the  earth  may  affect  us.  It  may 
well  be  cited  in  its  favour  that  it  is  certain  that  the  sun  affects  our 
magnetism  (it  is  doubtful  whether  it  does  so  /'^mediately,  or 
mediately  by  giving  different  degrees  of  warmth  to  different  parts  of 


250  GEORGE   BIDDELL  AIRY. 

the  earth),  and  it  is  believed  on  inferior  evidence  that  the  moon  also 
affects  it.  It  may  therefore  seem  not  impossible  or  implausible  that 
other  celestial  bodies  may  affect  perhaps  others  of  the  powers  of 
nature  about  us.  But  theie  I  must  sj:op.  The  denial  of  the  impos- 
sibility is  no  assertion  of  the  truth  br  probability,  and  I  absolutely 
decline  to  take  either  side — either  that  the  influences  are  real,  or 
that  the  influences  are  unreal— till  I  see  evidence  of  their  effects. 

Such  evidence  it  is  extremely  difficult  to  extract  from  ordinary 
facts  of  observation.  I  have  alluded  to  the  sun's  daily  disturbance 
of  the  magnet  as  one  of  the  most  certain  of  influences,  yet  if  you 
were  to  observe  the  magnet  for  a  single  day  or  perhaps  for  several 
days,  you  might  see  no  evidence  of  that  influence,  so  completely  is 
it  involved  with  other  disturbances  whose  causes  and  laws  are  totally 
unknown. 

I  believe  that,  in  addition  to  the  effects  ascribable  to  Newtonian 
gravitation  (as  general  motion  of  the  earth,  precession  of  the 
equinoxes,  and  tides),  this  magnetic  disturbance  is  the  only  one  yet 
established  as  depending  on  an  external  body.  Men  in  general, 
however,  do  not  think  so.  It  appears  to  be  a  law  of  the  human 
mind,  to  love  to  trace  an  effect  to  a  cause,  and  to  be  ready  to 
assent  to  any  specious  cause.  Thus  all  practical  men  of  the  lower 
classes,  even  those  whose  pecuniary  interests  are  concerned  in  it, 
believe  firmly  in  the  influence  of  the  moon  upon  the  winds  and 
the  weather.  I  believe  that  every  careful  examiner  of  recorded 
facts  (among  whom  I  place  myself  as  regards  the  winds)  has  come 
to  the  conclusion  that  the  influence  of  the  moon  is  not  discoverable. 

I  point  out  these  two  things  (magnetic  disturbances  and 
weather)  as  tending  to  shew  that  notoriety  or  the  assumed  consent 
of  practical  men,  are  of  no  value.  The  unnotorious  matter  may  be 
quite  certain,  the  notorious  matter  may  have  no  foundation.  Every- 
thing must  stand  on  its  own  evidence,  as  completely  digested  and 
examined. 

Of  such  evidence  the  planetary  influence  has  not  a  particle. 

My  intended  short  note  has,  in  the  course  of  writing,  grown  up 
into  a  discourse  of  very  unreasonable  length  ;  and  it  is  possible  that 
a  large  portion  of  it  has  only  increased  obscurity.  At  any  rate  I  can 
add  nothing,  I  believe,  which  can  help  to  explain  more  fully  my 
views  on  this  matter. 


AT  GREENWICH   OBSERVATORY — 1856  TO    1 866.        25! 

In  this  year  (1862,  June  9th)  Airy  received  the  Honorary 
Degree  of  LL.D.  in  the  University  of  Cambridge.  He  was 
nominated  by  the  Duke  of  Devonshire,  as  appears  from  the 
following  letter : 


LISMORE  CASTLE,  IRELAND, 
April  I9//&,  1862. 


MY  DEAR  SIR, 


It  is  proposed  according  to  usage  to  confer  a  considerable 
number  of  Honorary  Degrees  on  the  occasion  of  my  first  visit  to 
Cambridge  as  Chancellor  of  the  University. 

I  hope  that  you  will  allow  me  to  include  your  name  in  that 
portion  of  the  list  which  I  have  been  invited  to  draw  up. 

The  ceremony  is  fixed  for  the  loth  of  June. 

I  am,  my  dear  Sir, 

Yours  very  truly, 

DEVONSHIRE. 

The  Astronomer  Royal 


Airy's  reply  was  as  follows  : 

ROYAL  OBSERVATORY,  GREENWICH, 
LONDON,  S.E. 

1862,  April  21. 

MY  LORD  DUKE, 

I  am  exceedingly  gratified  by  your  communication  this 
day  received,  conveying  a  proposal  which  I  doubt  not  is  suggested 
by  your  Grace's  recollection  of  transactions  now  many  years  past. 

I  have  always  been  desirous  of  maintaining  my  connection  with 
my  University,  and  have  in  various  ways  interested  myself  practically 
in  its  concerns.  It  would  give  me  great  pleasure  to  have  the  con- 
nection strengthened  in  the  flattering  way  which  you  propose. 


252  GEORGE   BIDDELL  AIRY. 

I  had  conceived  that  alumni  of  the  University  were  not  admissible 
to  honorary  degrees ;  but  upon  this  point  the  information  possessed 
by  your  Grace,  as  Chancellor  of  the  University,  cannot  be  disputed. 

'"•  -I  am,  rj0y  Lord  Duke, 
Your  Grace's  very  faithful  servant, 

G.    B.    AIRY. 
His  Grace 

The  Duke  of  Devonshire. 


There  were  in  all  19  Honorary  Degrees  of  Doctor  of  Laws 
conferred  on  the  9th  of  June,  including  men  of  such  eminence 
as  Armstrong,  Faraday,  and  Fairbairn. 


1863 

In  this  year  there  were  several  schemes  for  a  Railway 
through  the  lower  part  of  Greenwich  Park,  the  most 
important  being  the  scheme  of  the  London,  Chatham  and 
Dover  Railway  Company.  In  reference  to  this  scheme  the 
Report  to  the  Visitors  states  "  I  may  say  briefly  that  I 
believe  that  it  would  be  possible  to  render  such  a  railway 
innocuous  to  the  Observatory  ;  it  would  however  be  under 
restrictions  which  might  be  felt  annoying  to  the  authorities 
of  the  Railway,  but  whose  relaxation  would  almost  ensure 
ruin  to  the  Observatory." — "  The  meridional  observations  of 
Mars  in  the  Autumn  of  1862  have  been  compared  with  those 
made  at  the  Observatory  of  Williamstown,  near  Melbourne, 
Australia,  and  they  give  for  mean  solar  parallax  the  value 
8'932",  exceeding  the  received  value  by  about  Jjth  part.  (A 
value  nearly  identical  with  this  8*93"  has  also  been  found  by 
comparing  the  Pulkowa  and  Cape  of  Good  Hope  Observa- 
tions.)"— "The  results  of  the  new  Dip-Instrument  in  1861 
and  1862  appear  to  give  a  firm  foundation  for  speculations 
on  the  state  and  change  of  the  dip.  As  a  general  result, 


AT   GREENWICH   OBSERVATORY— 1856   TO    l866.        253 

I  may  state  as  probable  that  the  value  of  dip  in  the  middle 
of  1843  was  about  69°  i',  and  in  the  middle  of  1862  about 
68°  u'.  The  decrease  of  dip  appears  to  be  more  rapid  in  the 
second  half  of  this  interval  than  in  the  first ;  the  dip  at 
beginning  of  1853  being  about  68°44'." — With  reference  to 
the  re-determination  of  the  longitude  of  Valencia,  it  is  stated 
that  "  The  concluded  longitude  agrees  almost  exactly  with 
that  determined  by  the  transmission  of  chronometers  in  1844; 
and  entitles  us  to  believe  that  the  longitudes  of  Kingstown 
and  Liverpool,  steps  in  the  chronometer  conveyance,  were 
determined  with  equal  accuracy." — "The  computations,  for 
inferring  the  direction  and  amount  of  movement  of  the  Solar 
System  in  space  from  the  observed  proper  motions  of  1167 
stars,  have  been  completed.  The  result  is,  that  the  Sun 
is  moving  towards  a  point,  R.A.  264°,  N.P.D.  65°  (not  very 
different  from  Sir  W.  HerschePs,  but  depending  much  in 
N.P.D.  on  the  accuracy  of  Bradley's  quadrant  observations), 
and  that  its  annual  motion  subtends,  at  the  distance  of  a  star 
of  the  first  magnitude,  the  angle  0-4".  But  the  comparison, 
of  the  sum  of  squares  of  apparent  proper  motions  uncorrected, 
with  the  sum  of  squares  of  apparent  proper  motions  corrected 
for  motion  of  Sun,  shews  so  small  an  advance  in  the  explana- 
tion of  the  star's  apparent  movements  as  to  throw  great 
doubt  on  the  certainty  of  results ;  the  sum  of  squares  being 
diminished  by  only  ^th  part." — "  I  had  been  writing  strongly 
to  Maclear  on  the  delays  in  publishing  both  the  geodetic 
work  and  the  Star  Catalogue  at  the  Cape  of  Good  Hope  :  he 
resolves  to  go  on  with  these  works.  In  December  I  am  still 
very  urgent  about  the  geodesy." 

Of  private  history:  There  was  the  usual  short  visit  to 
Playford  at  the  beginning  and  end  of  the  year. — "From 
June  2/th  to  August  roth  I  was  travelling  in  the  North  and 
West  of  Scotland  with  my  wife,  my  youngest  son  Osmund, 
and  my  daughter  Annot." 


254  GEORGE   BIDDELL   AIRY. 

In  this  year  the  offer  of  Knighthood  (for  the  third  time) 
was  made  to  Airy  through  the  Rt  Hon.  Sir  George  C.  Lewis, 
Bart.  The  offer  was  accepted  on  Feb.  I2th,  1863,  but  on  the 
same  day  a  second  letter  was  written  as  follows  : 

1863,  Feb.  12. 
DEAR  SIR, 

I  am  extremely  ignorant  of  all  matters  connected  with 
court  ceremonial,  and  in  reference  to  the  proposed  Knighthood 
would  ask  you  :  — 

1.  I  trust  that  there  is  no  expense  of  fees.     To  persons  like 
myself  of  small  fortune  an  honour  may  sometimes  be  somewhat  dear. 

2.  My   highest   social   rank   is  that  given  by  my  Academical 
Degree  of  D.C.L.  which  I  hold  in  the  Universities  of  Oxford  and 
Cambridge.     In  regard  to  costume,  would  it  be  proper  that  I  should 
appear  in  the  scarlet  gown  of  that  degree  ?  or  in  the  ordinary  Court 
Dress  ? 

I  am,  Dear  Sir, 

Yours  very  faithfully, 

G.  B.  AIRY. 

The  Right  Honourable 

Sir  George  C.  Lewis,  Bart., 


To  this  letter  Sir  G.  C.  Lewis  replied  that  the  fees  would 
amount  to  about  ,£30,  an  intimation  which  produced  the 
following  letter  : 

ROYAL  OBSERVATORY,  GREENWICH,  S.E. 

1863,  Fed.  \tyh. 
DEAR  SIR, 

I  have  to  acknowledge  your  letter  of  yesterday  :  and  I 
advert  to  that  part  of  it  in  which  it  is  stated  that  the  Fees  on  Knight- 
hood amount  to  about  ^30. 

Twenty-seven  years  ago  the  same  rank  was  offered  to  me  by 
Lord  John  Russell  and  Mr  Spring  Rice  (then  Ministers  of  the 
Crown),  with  the  express  notice  that  no  fees  would  be  payable.  I 
suppose  that  the  usage  (whatever  it  be)  on  which  that  notice  was 
founded  still  subsists. 


AT  GREENWICH   OBSERVATORY  —  1856  TO    1  866.        255 

To  a  person  whose  annual  income  little  more  than  suffices  to 
meet  the  annual  expenses  of  a  very  moderate  establishment,  an 
unsought  honour  may  be  an  incumbrance.  It  appears,  at  any  rate, 
opposed  to  the  spirit  of  such  an  honour,  that  it  should  be  loaded 
with  Court  Expenses  in  its  very  creation. 

I  hope  that  the  principle  stated  in  1835  may  serve  as  precedent 
on  this  occasion. 

I  am,  dear  Sir, 

Your  very  faithful  servant, 

G.  B.  AIRY. 

The  Right  Honourable 

Sir  G.  C.  Lewis,  Bart., 


No  intimation  however  was  received  that  the  fees  would 
be  remitted  on  the  present  occasion,  and  after  consideration 
the  proposed  Knighthood  was  declined  in  the  following 
letter  : 

ROYAL  OBSERVATORY,  GREENWICH,  S.E. 

1863,  April  15. 
DEAR  SIR, 

I  have  frequently  reflected  on  the  proposal  made  by  you 
of  the  honour  of  Knighthood  to  myself.  I  am  very  grateful  to  you 
for  the  favourable  opinion  which  you  entertain  in  regard  to  my 
supposed  claims  to  notice,  and  for  the  kindness  with  which  you  pro- 
posed publicly  to  express  it.  But  on  consideration  I  am  strongly 
impressed  with  the  feeling  that  the  conditions  attached  by  established 
regulation  to  the  conferring  of  such  an  honour  would  be  unacceptable 
to  me,  and  that  the  honour  itself  would  in  reality,  under  the  circum- 
stances of  my  family-establishment  and  in  my  social  position,  be  an 
incumbrance  to  me.  And  finally  I  have  thought  it  best  most 
respectfully,  and  with  a  full  sense  of  the  kindness  of  yourself  and  of 
the  Queen's  Government  towards  me,  to  ask  that  the  proposal  might 
be  deferred. 

There  is  another  direction  in  which  a  step  might  be  made,  affect- 
ing my  personal  position  in  a  smaller  degree,  but  not  tending  to 
incommode  me,  which  I  would  ask  leave  to  submit  to  your  considera- 
tion. It  is,  the  definition  of  the  Rank  of  the  Astronomer  Royal. 
The  singular  character  of  the  office  removes  it  from  ordinary  rules  of 


256  GEORGE   BIDDELL  AIRY. 

rank,  and  sometimes  may  produce  a  disagreeable  contest  of  opinions. 
The  only  offices  of  similar  character  corresponding  in  other  conditions 
to  that  of  the  British  Astronomer  Royal  are  those  of  the  Imperial 
Astronomers  at  Pulkowa  -(St  Petersburg)  and  Paris.  In  Russia, 
where  every  rank  is  clearly  defined  by  that  of  military  grade,  the 
Imperial  Astronomer  has  the  rank  of  Major-General.  In  France,  the 
definition  is  less  precise,  but  the  present  Imperial  Astronomer  has 
been  created  (as  an  attachment  of  rank  to  the  office)  a  Senator  of 
the  Empire. 

I  am,  dear  Sir, 

Your  very  faithful  servant, 

G.  B.  AIRY. 
The  Rt  Hon.  Sir  George  C.  Lewis,  Bart., 


Sir  G.  C.  Lewis  died  before  receiving  this  letter,  and  the 
letter  was  afterwards  forwarded  to  Lord  Palmerston.  Some 
correspondence  followed  between  Lord  Palmerston  and  Airy 
on  the  subject  of  attaching  a  definite  rank  to  the  office  of 
Astronomer  Royal,  as  proposed  in  the  above  letter.  But  the 
Home  Office  (for  various  reasons  set  forth)  stated  that  the 
suggestion  could  not  be  complied  with,  and  the  whole  subject 
dropped. 


1864 

The  following  remarks  are  extracted  from  the  Report  of 
the  Astronomer  Royal  to  the  Board  of  Visitors. — "  In  a  very 
heavy  squall  which  occurred  in  the  gale  of  December  2  of  last 
year,  the  stay  of  the  lofty  iron  pillar  ousi^e  of  the  Park  Rails, 
which  carried  our  telegraph  wires,  gave  way,  and  the  pillar 
and  the  whole  system  of  wires  fell." — "  An  important  altera- 
tion has  been  made  in  the  Magnetic  Observatory.  For  several 
years  past,  various  plans  have  been  under  consideration  for 
preventing  large  changes  of  temperature  in  the  room  which 
contains  the  magnetic  instruments.  At  length  I  determined 


AT   GREENWICH   OBSERVATORY— 1856  TO    l866.       257 

to  excavate  a  subterraneous  room  or  cellar  under  the  original 
room.  The  work  was  begun  in  the  last  week  in  January,  and 
in  all  important  points  it  is  now  finished." — "  In  the  late 
spring,  some  alarm  was  occasioned  by  the  discovery  that  the 
Parliamentary  Standard  of  the  Pound  Weight  had  become 
coated  with  an  extraneous  substance  produced  by  the  decom- 
position of  the  lining  of  the  case  in  which  it  was  preserved. 
It  was  decided  immediately  to  compare  it  with  the  three 
Parliamentary  Copies,  of  which  that  at  the  Observatory  is 
one.  The  National  Standard  was  found  to  be  entirely  un- 
injured."— "  On  November  16  of  last  year,  the  Transit  Instru- 
ment narrowly  escaped  serious  injury  from  an  accident.  The 
plate  chain  which  carries  the  large  western  counterpoise 
broke.  The  counterpoise  fell  upon  the  pier,  destroying  the 
massive  gun-metal  wheels  of  the  lifting  machinery,  but  was 
prevented  from  falling  further  by  the  iron  stay  of  the  gas- 
burner  flue." — "  The  Prismatic  Spectrum- Apparatus  had  been 
completed  in  1863.  Achromatic  object-glasses  are  placed  on 
both  sides  of  the  prism,  so  that  each  pencil  of  light  through 
the  prism  consists  of  parallel  rays ;  and  breadth  is  given  to 
the  spectrum  by  a  cylindrical  lens.  The  spectral  lines  are 
seen  straighter  than  before,  and  generally  it  is  believed  that 
their  definition  is  improved." — "  For  observation  of  the  small 
planets,  a  convention  has  been  made  with  M.  Le  Verrier. 
From  new  moon  to  full  moon,  all  the  small  planets  visible  to 
I3h  are  observed  at  the  Royal  Observatory  of  Greenwich. 
From  full  moon  to  new  moon,  all  are  observed  at  the  Imperial 
Observatory  of  Paris.  The  relief  gained  in  this  way  is  very 
considerable." — "  In  determining  the  variations  in  the  power  of 
the  horizontal-force  and  vertical-force  magnets  depending  on 
temperature,  it  was  found  by  experiment  that  this  depended 
materially  on  whether  the  magnet  was  heated  by  air  or  by 
water,  and  '  The  result  of  these  experiments  (with  air)  is  to 
give  a  coefficient  for  temperature  correction  four  or  five  times 
as  great  as  that  given  by  the  water-heatings.' " — "  With  regard 
to  the  discordances  of  the  results  of  observations  of  dip- 
A.  B,  17 


258  GEORGE  BIDDELL  AIRY. 

needles,  experiments  had  been  made  with  needles  whose 
breadth  was  in  the  plane  passing  through  the  axis  of  rotation, 
and  it  appeared  that  the  means  of  extreme  discordances  were, 
for  an  ordinary  needle  n'  45'Vand  for  a  flat  needle  3'  27"," 
and  the  Report  continues  thus :  "  After  this  I  need  not  say 
that  I  consider  it  certain  that  the  small  probable  errors  which 
have  been  attributed  to  ordinary  needles  are  a  pure  delusion." 
— The  Report  states  that  in  the  various  operations  connected 
with  the  trials  and  repairs  of  chronometers,  and  the  system  of 
time-signals  transmitted  to  various  time-balls  and  clocks, 
about  one-fourth  of  the  strength  of  the  Observatory  is  em- 
ployed, and  it  continues  thus  :  "  Viewing  the  close  dependence 
of  Nautical  Astronomy  upon  accurate  knowledge  of  time, 
there  is  perhaps  no  department  of  the  Observatory  which 
answers  more  completely  to  the  original  utilitarian  intentions 
of  the  Founder  of  the  Royal  Observatory." — "  With  regard  to 
the  proposal  of  time-signals  at  the  Start  Point,  it  appears  that 
communications  referring  to  this  proposal  had  passed  between 
the  Board  of  Admiralty  and  the  Board  of  Trade,  of  which  the 
conclusion  was,  that  the  Board  of  Trade  possessed  no  funds 
applicable  to  the  defraying  of  the  expenses  attending  the 
execution  of  the  scheme.  And  the  Admiralty  did  not  at 
present  contemplate  the  establishment  of  these  time-signals 
under  their  own  authority." — Amongst  other  Papers  in  this 
year,  Airy's  Paper  entitled  "First  Analysis  of  177  Magnetic 
Storms,"  &c.,  was  read  before  the  Royal  Society. 

Of  private  history  :  "  There  was  the  usual  visit  to  Playford 
in  the  beginning  of  the  year. — From  June  8th  to  23rd  I  made 
an  excursion  with  my  son  Hubert  to  the  Isle  of  Man,  and  the 
Lake  District. — From  Sept.  7th  to  I4th  I  was  on  a  trip  to 
Cornwall  with  my  two  eldest  sons,  chiefly  in  the  mining 
district. — In  August  of  this  year  my  eldest  (surviving)  daugh- 
ter, Hilda,  was  married  to  Mr  E.  J.  Routh,  Fellow  of  St  Peter's 
College,  Cambridge,  at  Greenwich  Parish  Church.  They  after- 
wards resided  at  Cambridge." 


AT  GREENWICH  OBSERVATORY— 1856  TO    1 866.       259 


1865 

"Our  telegraphic  communications  of  every  kind  were 
again  destroyed  by  a  snow-storm  and  gale  of  wind  which 
occurred  on  Jan.  28th,  and  which  broke  down  nearly  all  the 
posts  between  the  Royal  Observatory  and  the  Greenwich 
Railway  Station. — The  Report  to  the  Visitors  states  that 
'  The  only  change  of  Buildings  which  I  contemplate  as  at 
present  required  is  the  erection  of  a  fire-proof  Chronometer 
Room.  The  pecuniary  value  of  Chronometers  stored  in  the 
Observatory  is  sometimes  perhaps  as  much  as  .£8000.' — The 
South  Eastern  and  London  Chatham  and  Dover  scheme  for 
a  railway  through  the  Park  was  again  brought  forward.  There 
was  a  meeting  of  Sir  J.  Hanmer's  Committee  at  the  Observa- 
tory on  May  26th.  Mr  Stone  was  sent  hastily  to  Dublin  to 
make  observations  on  Earth-disturbance  by  railways  there. 
I  had  been  before  the  Committee  on  May  25th.  On  Sept.  ist 
I  approved  of  an  amended  plan.  In  reference  to  this  matter 
the  Report  states  that '  It  is  proper  to  remark  that  the  shake 
of  the  Altazimuth  felt  in  the  earthquake  of  1863,  Oct.  5th, 
when  no  such  shake  was  felt  with  instruments  nearer  to  the 
ground  (an  experience  which,  as  I  have  heard  on  private 
authority,  is  supported  by  observation  of  artificial  tremors), 
gives  reason  to  fear  that,  at  distances  from  a  railway  which 
would  sufficiently  defend  the  lower  instruments,  the  loftier 
instruments  (as  the  Altazimuth  and  the  Equatoreals)  would 
be  sensibly  affected.' — Some  of  the  Magnets  had  been  sus- 
pended by  steel  wires,  instead  of  silk,  of  no  greater  strength 
than  was  necessary  for  safety,  and  the  Report  states  that 
1  Under  the  pressure  of  business,  the  determination  of  various 
constants  of  adjustment  was  deferred  to  the  end  of  the  year. 
The  immediate  results  of  observation,  however,  began  to 
excite  suspicion ;  and  after  a  time  it  was  found  that,  in  spite 
of  the  length  of  the  suspending  wire  (about  8  feet)  the  torsion- 
coefficient  was  not  much  less  than  J.  The  wires  were  promptly 

17—2 


260  GEORGE   BIDDELL  AIRY. 

dismounted,  and  silk  skeins  substituted  for  them.  With  these, 
the  torsion-coefficient  is  about  ^f^.' — The  Dip-Instrument, 
which  had  given  great  trouble  by  the  irregularities  of  the  dip- 
results,  had  been  compared  wifh  two  dip-instruments  from 
Kew  Observatory,  which  gave  very  good  and  accordant 
results.  '  It  happened  that  Mr  Simms,  by  whom  our  instru- 
ments now  in  use  were  prepared,  and  who  had  personally 
witnessed  our  former  difficulties,  was  present  during  some  of 
these  experiments.  Our  own  instrument  being  placed  in  his 
hands  (Nov.  loth  to  ipth)  for  another  purpose,  he  sponta- 
neously re-polished  the  apparently  faultless  agate-bearings. 
To  my  great  astonishment,  the  inconsistencies  of  every  kind 
have  nearly  or  entirely  vanished.  On  raising  and  lowering 
the  needles,  they  return  to  the  same  readings,  and  the  dips 
with  the  same  needle  appear  generally  consistent.'  Some 
practical  details  of  the  polishing  process  by  which  this  result 
had  been  secured  are  then  given. — After  numerous  delays, 
the  apparatus  for  the  self-registration  of  Spontaneous  Earth 
Currents  was  brought  into  a  working  state  in  the  month  of 
March.  A  description  of  the  arrangement  adopted  is  given 
in  the  Report. — '  All  Chronometers  on  trial  are  rated  every 
day,  by  comparison  with  one  of  the  clocks  sympathetic  with 
the  Motor  Clock.  Every  Chronometer,  whether  on  trial  or 
returned  from  a  chronometer-maker  as  repaired,  is  tried  at 
least  once  in  the  heat  of  the  Chronometer-Oven,  the  tempera- 
ture being  usually  limited  to  90°  Fahrenheit ;  and,  guided  by 
the  results  of  very  long  experience,  we  have  established  it  as 
a  rule,  that  every  trial  in  heat  be  continued  through  three 
weeks/ — '  The  only  employment  extraneous  to  the  Observa- 
tory which  has  occupied  any  of  my  time  within  the  last  year 
is  the  giving  three  Lectures  on  the  Magnetism  of  Iron  Ships 
(at  the  request  of  the  Lords  of  the  Committee  of  Council  on 
Education)  in  the  Theatre  of  the  South  Kensington  Museum. 
The  preparations,  however,  for  these  Lectures,  to  be  given  in 
a  room  ill-adapted  to  them,  occupied  a  great  deal  of  my  own 
time,  and  of  the  time  of  an  Assistant  of  the  Observatory.' — 


AT   GREENWICH   OBSERVATORY— 1856  TO    l866.       26l 

'  Referring  to  a  matter  in  which  the  interests  of  Astronomy 
are  deeply  concerned,  I  think  it  right  to  report  to  the  Visitors 
my  late  representation  to  the  Government,  to  the  effect  that, 
in  reference  to  possible  observation  of  the  Transit  of  Venus 
in  1882,  it  will  be  necessary  in  no  long  time  to  examine 
the  coasts  of  the  Great  Southern  Continent."' 

Of  private  history :  "  There  were  the  usual  visits  to  Play- 
ford  at  the  beginning  and  end  of  the  year. — From  June  i8th 
to  26th  I  was  on  a  trip  in  Wales  with  my  sons  Hubert  and 
Osmund. — From  Sept.  6th  to  Oct.  2nd  I  was  staying  with 
most  of  my  family  at  Portinscale  near  Keswick  :  we  returned 
by  Barnard  Castle,  Rokeby,  &c." 


ft 

CHAPTER    VIII. 

AT  GREENWICH  OBSERVATORY — 1866  TO  1876. 

1866 

IN  this  year  the  cube  of  the  Transit  Circle  was  pierced, 
to  permit  reciprocal  observations  of  the  Collimators  without 
raising  the  instrument.  This  involved  the  construction  of 
improved  Collimators,  which  formed  the  subject  of  a  special 
Address  to  the  Members  of  the  Board  of  Visitors  on  Oct.  2ist 
1865. — From  the  Report  to  the  Visitors  it  appears  that  "  On 
May  23rd  1865,  a  thunderstorm  of  great  violence  passed  very 
close  to  the  Observatory.  After  one  flash  of  lightning,  I  was 
convinced  that  the  principal  building  was  struck.  Several 
galvanometers  in  the  Magnetic  Basement  were  destroyed. 
Lately  it  has  been  remarked  that  one  of  the  old  chimneys 
of  the  principal  building  had  been  dislocated  and  slightly 
twisted,  at  a  place  where  it  was  surrounded  by  an  iron  stay- 
band  led  from  the  Telegraph  Pole  which  was  planted  upon 
the  leads  of  the  Octagon  Room." — "  On  consideration  of  the 
serious  interruptions  to  which  we  have  several  times  been 
exposed  from  the  destruction  of  our  open-air  Park-wires 
(through  snow-storms  and  gales),  I  have  made  an  arrange- 
ment for  leading  the  whole  of  our  wires  in  underground  pipes 
as  far  as  the  Greenwich  Railway  Station." — "  The  Committee 
of  the  House  of  Commons,  to  whom  the  Greenwich  and 
Woolwich  Line  of  the  South  Eastern  Railway  was  referred, 
finally  assented  to  the  adoption  of  a  line  which  I  indicated, 
passing  between  the  buildings  of  the  Hospital  Schools  and 


AT   GREENWICH   OBSERVATORY— 1 866   TO    1876.       263 

the  public  road  to  Woolwich." — "The  Galvanic  Chro- 
nometer attached  to  the  S.  E.  Equatoreal  often  gave  us  a 
great  deal  of  trouble.  At  last  I  determined,  on  the  proposal 
of  Mr  Ellis,  to  attempt  an  extension  of  Mr  R.  L.  Jones's 
regulating  principle.  It  is  well  known  that  Mr  Jones  has 
with  great  success  introduced  the  system  of  applying  galvanic 
currents  originating  in  the  vibrations  of  a  normal  pendulum, 
not  to  drive  the  wheelwork  of  other  clocks,  but  to  regulate  to 
exact  agreement  the  rates  of  their  pendulums  which  were, 
independently,  nearly  in  agreement ;  each  clock  being  driven 
by  weight-power  as  before.  The  same  principle  is  now 

applied  to  the  chronometer The  construction  is  perfectly 

successful ;  the  chronometer  remains  in  coincidence  with  the 
Transit  Clock  through  any  length  of  time,  with  a  small 
constant  error  as  is  required  by  mechanical  theory." — "The 
printed  volume  of  Observations  for  1864  has  two  Appen- 
dixes; one  containing  the  calculations  of  the  value  of  the 
Moon's  Semi-diameter  deduced  from  295  Occupations 
observed  at  Cambridge  and  Greenwich  from  1832  to  1860, 
and  shewing  that  the  Occupation  Semi-diameter  is  less 
than  the  Telescopic  Semi-diameter  by  2";  the  other  con- 
taining the  reduction  of  the  Planetary  Observations  made  at 
the  Royal  Observatory  in  the  years  1831 — 1835  ;  filling  up 
the  gap,  between  the  Planetary  Reductions  1750 — 1830  made 
several  years  ago  under  my  superintendence,  and  the  Reduc- 
tions contained  in  the  Greenwich  Volumes  1836  to  the  present 
time  :  and  conducted  on  the  same  general  principles." — "  Some 
trouble  had  been  found  in  regulating  the  temperature  of  the 
Magnetic  Basement,  but  it  was  anticipated  that  in  future 
there  would  be  no  difficulty  in  keeping  down  the  annual  vari- 
ation within  about  5°  and  the  diurnal  variation  within  3°. — 
Longitudes  in  America  were  determined  in  this  year  by  way 
of  Valencia  and  Newfoundland  :  finished  by  Nov.  I4th." 

Of  private  history :  In  April  he  made  a  short  visit  to 
Ventnor  in  the  Isle  of  Wight. — From  June  I5th  to  July  23rd 
he  was  on  an  expedition  in  Norway  with  his  son  Osmund 


264  GEORGE   BIDDELL  AIRY. 

and  his  nephew  Gorell  Barnes.  —  There  was  probably  a  short 
stay  at  Play  ford  in  the  winter. 

In  this  and  in  the  previous  year  (1865)  the  free-thinking 
investigations  of  Colenso,  the  Bishop  of  Natal,  had  attracted 
much  notice,  and  had  procured  him  the  virulent  hostility  of  a 
numerous  section.  His  income  was  withheld  from  him,  and 
in  consequence  a  subscription  fund  was  raised-  for  his  support 
by  his  admirers.  Airy,  who  always  took  the  liberal  side  in 
such  questions,  was  a  subscriber  to  the  fund,  and  wrote  the 
following  letter  to  the  Bishop  : 

ROYAL  OBSERVATORY,  GREENWICH,  S.E., 
1865,  J^y  24- 


MY  LORD, 

With  many  thanks  I  have  to  acknowledge  your  kind 
recollection  of  me  in  sending  as  a  presentation  copy  the  work  on 
Joshua,  Judges,  and  especially  on  the  divided  authorship  of 
Genesis  ;  a  work  whose  investigations,  founded  in  great  measure  on 
severe  and  extensive  verbal  criticism,  will  apparently  bear  com- 
parison with  your  Lordship's  most  remarkable  examination  of 
Deuteronomy.  I  should  however  not  do  justice  to  my  own  appre- 
ciation if  I  did  not  remark  that  there  are  other  points  considered 
which  have  long  been  matters  of  interest  to  me. 

On  several  matters,  some  of  them  important,  my  present  conclu- 
sions do  not  absolutely  agree  with  your  Lordship's.  But  I  am  not 
the  less  grateful  for  the  amount  of  erudition  and  thought  carefully 
directed  to  definite  points,  and  above  all  for  the  noble  example  of 
unwearied  research  and  freedom  in  stating  its  consequences,  in 
reference  to  subjects  which  scarcely  ever  occupy  the  attention  of 
the  clergy  in  our  country. 

I  am,  My  Lord, 

Yours  very  faithfully, 

G.  B.  AIRY. 

The  Lord  Bishop  of  Natal. 

Here  also  is  a  letter  on  the  same  subject,  written  to 
Professor  Selwyn,  Professor  of  Divinity  at  Cambridge  :  — 


AT  GREENWICH   OBSERVATORY— 1 866  TO    1 8/6.       265 

ROYAL  OBSERVATORY,  GREENWICH, 
LONDON,  S.E., 

1866,  May  5. 

MY  DEAR  SIR, 

The  MS.  concerning  Colenso  duly  arrived. 

I  note  your  remarks  on  the  merits  of  Colenso.  I  do  not  write 
to  tell  you  that  I  differ  from  you,  but  to  tell  you  why  I  differ. 

I  think  that  you  do  not  make  the  proper  distinction  between  a 
person  who  invents  or  introduces  a  tool,  and  the  person  who  uses  it. 

The  most  resolute  antigravitationist  that  ever  lived  might  yet 
acknowledge  his  debt  to  Newton  for  the  Method  of  Prime  and 
Ultimate  Ratios  and  the  Principles  of  Fluxions  by  which  Newton 
sought  to  establish  gravitation. 

So  let  it  be  with  Colenso.  He  has  given  me  a  power  of  tracing 
out  truth  to  a  certain  extent  which  I  never  could  have  obtained 
without  him.  And  for  this  I  am  very  grateful. 

As  to  the  further  employment  of  this  power,  you  know  that  he 
and  I  use  it  to  totally  different  purposes.  But  not  the  less  do  I  say 
that  I  owe  to  him  a  new  intellectual  power. 

I  quite  agree  with  you,  that  the  sudden  disruption  of  the  old 
traditional  view  seems  to  have  unhinged  his  mind,  and  to  have  sent 
him  too  far  on  the  other  side.  I  would  not  give  a  pin  for  his 
judgment. 

Nevertheless,  I  wish  he  would  go  over  the  three  remaining  books 
of  the  Tetrateuch. 

I  know  something  of  Myers,  but  I  should  not  have  thought 
him  likely  to  produce  anything  sound  on  such  things  as  the  Hebrew 
Scriptures.  I  never  saw  his  "  Thoughts." 

I  am,  my  dear  Sir, 

Yours  very  truly, 

G.  B.  AIRY. 

Professor  Selwyn. 


The  following  letter  has  reference  to  Airy's  proposal  to 
introduce  certain  Physico-Mathematical  subjects  into  the 
Senate-House  Examination  for  B.A.  Honors  at  Cambridge. 
On  various  occasions  he  sharply  criticized  the  Papers  set  for 


266  GEORGE   BIDDELL   AIRY. 

the  Senate-House  Examination  and  the  Smith's  Prize 
Examination,  and  greatly  lamented  the  growing  importance 
of  pure  mathematics  and  the  comparative  exclusion  of 
physical  questions  in  those  examinations.  His  proposal  as 
finally  submitted  in  the  letter  that  follows  was  somewhat 
modified  (as  regards  the  mode  of  introducing  the  subjects) 
from  his  original  draft,  in  deference  to  the  opinions  of 
Whewell,  Adams,  Routh,  and  other  friends  to  whom  he  had 
submitted  it.  His  proposal  was  favourably  received  by  the 
Mathematical  Board,  and  recommendations  were  made  in 
the  direction,  though  not  to  the  extent,  that  he  desired,  and 
he  subsequently  submitted  a  Memorandum  on  those  recom- 
mendations : 

ROYAL  OBSERVATORY,  GREENWICH, 
1866,  May  ii. 

MY  DEAR  SIR, 

You  will  perceive,  from  perusal  of  the  enclosed 
paper,  that  I  have  acted  on  the  permission  which  you  kindly  gave 
me,  to  transmit  to  you  my  proposal  for  extension  of  the  mathematical 
education  of  the  University  in  the  Physical  direction. 

It  is  an  unavoidable  consequence  of  the  structure  of  the  Univer- 
sity that  studies  there  will  have  a  tendency  to  take  an  unpractical 
form  depending  much  on  the  personal  tastes  of  special  examiners. 
I  trust  that,  as  a  person  whose  long  separation  from  the  daily 
business  of  the  University  has  enabled  him  to  see  in  some  measure 
the  wants  of  the  external  scientific  and  practical  world,  I  may  be 
forgiven  this  attempt  to  bring  to  the  notice  of  the  University  my 
ideas  on  the  points  towards  which  their  attention  might  perhaps 
be  advantageously  turned. 

I  am,  my  dear  Sir, 

Very  faithfully  yours, 

G.  B.  AIRY. 

The  Rev.  Dr  Cartmell, 
Master  of  Christ's  College 
and  Vice- Chancellor. 


AT   GREENWICH   OBSERVATORY— 1 866  TO    1876.       267 


ROYAL  OBSERVATORY,  GREENWICH, 
1866,  May  ii. 

MY  DEAR  MR  VICE-CHANCELLOR, 

About  two  years  ago,  by  the  kindness  of  the  Univer- 
sity, an  opportunity  was  presented  to  me  of  orally  stating  what  I 
conceived  to  be  deficiencies  in  the  educational  course  of  the 
University  as  regards  mathematical  physics.  Since  that  time,  the 
consideration  of  those  deficiencies,  which  had  long  been  present  to 
me,  has  urged  itself  on  my  attention  with  greater  force  :  and  finally  I 
have  entertained  the  idea  that  I  might  without  impropriety  com- 
municate to  you  my  opinion,  in  a  less  fugitive  form  than  on  the 
occasion  to  which  I  have  alluded :  with  the  request  that,  if  you 
should  deem  such  a  course  appropriate,  you  would  bring  it  before 
the  Board  of  Mathematical  Studies,  and  perhaps  ultimately  make  it 
known  to  the  Resident  Members  of  the  Senate. 

I  will  first  give  the  list  of  subjects,  which  I  should  wish  to  see 
introduced,  and  to  the  prosecution  of  which  the  generally  admirable 
course  of  the  University  is  remarkably  well  adapted :  and  I  will  then, 
without  entering  into  every  detail,  advert  to  the  process  by  which  I 
think  it  probable  the  introduction  of  these  subjects  could  be  effected. 

In  the  following  list,  the  first  head  is  purely  algebraical,  and  the 
second  nearly  so :  but  they  are  closely  related  to  observational 
science,  and  to  the  physical  subjects  which  follow.  Some  of  the 
subjects  which  I  exhibit  on  my  list  are  partially,  but  in  my  opinion 
imperfectly,  taught  at  present.  I  entirely  omit  from  my  list  Physical 
Optics,  Geometrical  Astronomy,  and  Gravitational  Astronomy  of 
Points :  because,  to  the  extent  to  which  Academical  Education 
ought  to  go,  I  believe  that  there  is  no  teaching  on  these  sciences 
comparable  to  that  in  the  University  of  Cambridge.  (It  is,  of 
course,  still  possible  that  improvements  may  be  made  in  the  books 
commonly  used.)  It  might,  however,  be  a  question,  whether,  as 
regards  the  time  and  manner  of  teaching  them,  some  parts  of  these 
subjects  might  ultimately  be  associated  with  the  other  subjects 
included  in  my  list. 

I.     List  of  subjects  proposed  for  consideration. 

(i)  Partial  Differential  Equations  to  the  second  order,  with 
their  arbitrary  functions :  selected  principally  with  reference  to  the 
physical  subjects. 


268  GEORGE  BIDDELL  AIRY. 

(2)  The  Theory  of  Probabilities  as  applied  to  the  combination 
of  Observations. 

(3)  Mechanics  (including  Hydraulic  Powers)  in  the  state  which 
verges  upon  practical  application,  and  especially  including  that  part 
in  which  the  abstract  ideas  of  powe^  and  duty  occur. 

(4)  Attractions.     This  subject   is   recognized   in   the    existing 
course  of  the  University  :  but,  so  far  as  I  can  infer  from  examina- 
tion-papers, it  appears  to  be  very  lightly  passed  over. 

(5)  The  Figure  of  the  Earth,  and  its  consequences,  Precession, 
&c.     I  believe  that  the  proposal  is  sanctioned,  of  adopting  some 
part  of  this  theory  in  the  ordinary  course ;  but  perhaps  hardly  so  far 
as  is  desirable. 

(6)  The  Tides. 

(7)  Waves  of  Water. 

(8)  Sound  (beginning  with  Newton's  investigation) ;   Echoes  ; 
Pipes  and  Vibrating  Strings ;  Acoustics ;  the  Mathematical  part  of 
Music. 

(9)  Magnetism,     terrestrial     and     experimental,     and     their 
connection. 

(I  omit  for  the  present  Mineralogy  and  Mathematical  Electricity.) 
This  list  of  subjects  appears  formidable :  but  they  are  in  reality 

easy,   and   would   be   mastered   in    a    short   time    by   the    higher 

Wranglers. 

II.     Mode  of  introducing  these  subjects  into  the  University. 

After  much  consideration,  and  after  learning  the  opinions  of 
several  persons  whose  judgment  claims  my  deepest  respect,  I 
propose  the  gradual  introduction  of  these  subjects  into  the 
Examination  for  Honors  at  admission  to  the  B.A.  Degree,  as 
soon  as  the  preparation  of  Books  and  the  readiness  of  Examiners 
shall  enable  the  University  to  take  that  step.  I  conceive  that,  by  a 
judicious  pruning  of  the  somewhat  luxuriant  growth  of  Pure  Algebra, 
Analytical  Geometry,  and  Mere  Problems,  sufficient  leisure  may  be 
gained  for  the  studies  of  the  undergraduates,  and  sufficient  time  for 
the  questions  of  the  examiners.  I  do  not  icontemplate  that  the 
students  could  advance  very  far  into  the  subjects ;  but  I  know  the 
importance  of  beginning  them ;  and,  judging  from  the  train  of 
thoughts,  of  reading,  and  of  conversation,  among  the  Bachelors  with 
whom  I  associated  many  years  ago,  I  believe  that  there  is  quite  a 
sufficient  number  who  will  be  anxious  to  go  deep  into  the  subjects  if 
they  have  once  entered  into  them.  If  six  Wranglers  annually  would 


AT   GREENWICH   OBSERVATORY — 1 866   TO    1876.       269 

take  them  up,  my  point  would  be  gained.  The  part  which  these 
gentlemen  might  be  expected,  in  a  short  time,  to  take  in  the  govern- 
ment of  the  University,  would  enable  them  soon  to  act  steadily  upon  the 
University  course  :  the  efficiency  of  the  University  instruction  would 
be  increased  ;  and  the  external  character  of  the  University  would  be 
raised. 

The  real  difficulties,  and  they  are  not  light  ones,  would  probably 
be  found  in  providing  Examiners  and  Books.  At  present,  both  are 
wanting  within  the  University.  Where  there  is  a  great  and  well- 
founded  objection  to  intrusting  examinations  to  persons  foreign  to 
the  University,  and  where  the  books  have  to  be  created  with  labour 
and  with  absolute  outlay  of  money  (for  their  sale  could  never  be 
remunerative),  the  progress  must  be  slow.  Still  progress  would  be 
certain,  if  the  authorities  of  the  University  should  think  the  matter 
deserving  of  their  hearty  encouragement. 

Requesting  that  you  and  the  Members  of  the  University  will 
accept  this  proposal  as  an  indication  of  my  deep  attachment  to  my 
University, 

I  am, 

My  dear  Mr  Vice- Chancellor, 

Your  very  faithful  servant, 

G.  B.  AIRY. 

The  Rev.  Dr  Cartmell, 
&c.  &*c. 

Vice- Chancellor  of  the  University  of  Cambridge. 


1867 

"In  this  year  it  was  arranged  that  my  Treasury  accounts 
were  to  be  transferred  to  the  Admiralty,  making  the  simplifi- 
cation which  I  had  so  long  desired. — From  the  Report  to  the 
Visitors  it  appears  that  a  relic  of  the  Geodetic  operations 
commenced  in  1787  for  connecting  the  Observatories  of 
Greenwich  and  Paris,  in  the  shape  of  an  observing  cabin  on 
the  roof  of  the  Octagon  Room,  was  shifted  and  supported  in 
such  a  manner  that  the  pressure  on  the  flat  roof  was  entirely 
avoided. — With  regard  to  the  Transit  Circle,  the  new  Colli- 
mators  with  telescopes  of  seven  inches  aperture  had  been 


2/0  GEORGE   BIDDELL  AIRY. 

mounted.  When  the  Transit  Telescope  directed  vertically  is 
interposed,  the  interruptions  in  the  central  cube  impair  the 
sharpness  of  definition,  still  leaving  it  abundantly  good  for 
general  use.  It  had  been  regarded  as  probable  that  the 
astronomical  flexure  of  the  telescope,  after  cutting  away 
small  portions  of  the  central  cube,  would  be  found  sensibly 
changed  :  and  this  proved  to  be  the  case.  1*he  difference  of 
flexures  of  the  two  ends  has  been  altered  more  than  a  second 
of  arc. — Referring  to  a  new  Portable  Altazimuth  which  had 
lately  been  tested,  the  Report  states  as  follows :  '  I  may 
mention  that  a  study  of  defects  in  the  vertical  circle  of  a 
small  Altazimuth  formerly  used  by  me,  and  an  inspection  of 
the  operations  in  the  instrument-maker's  work-shop,  have 
convinced  me  that  the  principal  error  to  be  feared  in  instru- 
ments of  this  class  is  ovality  of  the  graduated  limb ;  this 
cannot  be  eliminated  by  two  microscopes,  and  such  an  instru- 
ment should  never  be  fitted  with  two  only.  Our  instrument 
has  four.' — '  In  Osier's  Anemometer,  a  surface  of  2  square  feet 
is  now  exposed  to  the  wind  instead  of  one  foot  as  formerly; 
and  the  plate  is  supported  by  weak  vertical  springs  instead 
of  rods  running  on  rollers.  Its  indications  are  much  more 
delicate  than  formerly.' — 'The  Meteors  on  Nov.  I4th  were 
well  observed.  Eight  thousand  and  three  hundred  were 
registered.  The  variations  of  frequency  at  different  times 
were  very  well  noted.  The  points  of  divergence  were  care- 
fully determined.' — Referring  to  the  gradual  improvement  in 
the  steadiness  of  chronometers  from  1851  to  1866,  it  appears 
that  from  1851  to  1854  the  'trial  number'  (which  is  a  com- 
bination of  changes  of  weekly  rate  representing  the  fault  of 
the  chronometer)  varied  from  34-8*  to  52'5S,  while  from  1862 
to  1866  it  varied  from  2T2S  to  2  5 '8s. — The  following  state- 
ment will  shew  the  usual  steadiness  of  the  Great  Clock  on 
the  Westminster  Palace :  On  38  per  cent,  of  days  of  observa- 
tion, the  clock's  error  was  below  Is.  On  38  per  cent,  the 
error  was  between  Is  and  2s.  On  21  per  cent,  it  was  between 
2s  and  3s.  On  2  per  cent,  between  3s  and  4s.  On  i  per  cent. 


AT  .GREENWICH   OBSERVATORY — 1 866  TO    1 8/6.       271 

between  4s  and  5s. — The  Report  contains  an  account  of  the 
determination  of  the  longitude  of  Cambridge  U.S.  by  Dr 
B.  A.  Gould,  by  means  of  galvanic  currents  through  the 
Atlantic  Cable,  in  the  spring  of  1867:  and  advantage  was 
taken  of  this  opportunity  for  re-determining  the  longitude  of 
Feagh  Main  near  Valencia  in  Ireland.  The  longitude  of 
Feagh  Main,  found  by  different  methods  is  as  follows  :  By 
chronometers  in  1844,  4im  23'23S ;  by  galvanic  communi- 
cation with  Knight's  Town  in  1862,  4im23'37s;  by  galvanic 
communication  with  Foilhommerum  in  1866,  4im  2^'igs. 
The  collected  results  for  longitude  of  Cambridge  U.S.  from 
different  sources  are:  By  moon-culminators  (Walker  in  1851, 
and  Newcomb  in  1862-3),  4h  44™  28'42S  and  4h  44m  29'56S 
respectively;  by  Eclipses  (Walker  in  1851),  4h  44™  29'64S; 
by  occultations  of  Pleiades  (Peirce  1838 — 1842,  and  1856 — 
1861),  4h  44m  29-9 Is  and  4h  44™  3O*9OS  respectively;  by  chro- 
nometers (W.  C.  Bond  in  1851,  and  G.  P.  Bond  in  1855), 
4h  44m  30'66S  and  4h  44™  3 1  -89s  respectively ;  by  Atlantic 
Cable  1866,  4h  44™  3O'99S. — After  noticing  that  many  meteor- 
ological observatories  had  suddenly  sprung  up  and  had  com- 
menced printing  their  observations  in  detail,  the  Report 
continues  thus  :  '  Whether  the  effect  of  this  movement  will  be 
that  millions  of  useless  observations  will  be  added  to  the 
millions  that  already  exist,  or  whether  something  may  be 
expected  to  result  which  will  lead  to  a  meteorological  theory, 
I  cannot  hazard  a  conjecture.  This  only  I  believe,  that  it 
will  be  useless,  at  present,  to  attempt  a  process  of  mechanical 
theory;  and  that  all  that  can  be  done  must  be,  to  connect 
phaenomena  by  laws  of  induction.  But  the  induction  must 
be  carried  out  by  numerous  and  troublesome  trials  in 
different  directions,  the  greater  part  of  which  would  probably 
be  failures.' — There  was  this  year  an  annular  eclipse;  I 
made  large  preparations  at  the  limits  of  the  annularity; 
failed  entirely  from  very  bad  weather." — In  this  year  Airy 
contributed  a  Paper  to  the  Institution  of  Civil  Engineers  '  On 
the  use  of  the  Suspension  Bridge  with  stiffened  roadway  for 


2/2  GEORGE   BIDDELL  AIRY. 

Railway  and  other  Bridges  of  Great  Span,'  for  which  a 
Telford  Medal  was  awarded  to  him  by  the  Council  of  the 
Institution.  And  he  communicated  several  Papers  to  the 
Royal  Society  and  the  Royal  Astronomical  Society. 

Of  private  history :  There  was  the  usual  visit  to  Playford 
in  January. — In  April  there  was  a  short  run  to  Alnwick  and 
the  neighbourhood,  in  company  with  Mr  anct  Mrs  Routh. — 
From  June  2/th  to  July  4th  he  was  in  Wales  with  his  two 
eldest  sons,  visiting  Uriconium,  &c.  on  his  return. — From 
August  8th  to  Sept.  ;th  he  spent  a  holiday  in  Scotland 
and  the  Lake  District  of  Cumberland  with  his  daughter 
Christabel,  visiting  the  Langtons  at  Barrow  House,  near 
Keswick,  and  Isaac  Fletcher  at  Tarn  Bank. 

In  June  of  this  year  (1867)  Airy  was  elected  an  Honorary 
Fellow  of  his  eld  College  of  Trinity  in  company  with  Connop 
Thirlwall,  the  Bishop  of  St  David's.  They  were  the  first 
Honorary  Fellows  elected  by  the  College.  The  announce- 
ment was  made  in  a  letter  from  the  Master  of  Trinity  (W.  H. 
Thompson),  and  Airy's  reply  was  as  follows : 

ROYAL  OBSERVATORY,  GREENWICH, 
LONDON,  S.E. 

1867,  June  i2th. 
MY  DEAR  MASTER, 

I  am  very  much  gratified  by  your  kind  note  received 
this  morning,  conveying  to  me  the  notice  that  the  Master  and 
Sixteen  Senior  Fellows  had  elected  me,  under  their  new  powers, 
as  Honorary  Fellow  of  the  College. 

It  has  always  been  my  wish  to  maintain  a  friendly  connection 
with  my  College,  and  I  am  delighted  to  receive  this  response  from 
the  College.  The  peculiar  form  in  which  the  reference  to  the 
Statute  enables  them  to  put  it  renders  it  doubly  pleasing. 

As  the  Statute  is  new,  I  should  be  obliged  by  a  copy  of  it.  And, 
at  any  convenient  time,  I  should  be  glad  to  know  the  name  of  the 
person  with  whom  I  am  so  honorably  associated. 

I  am,  My  dear  Master, 

Very  faithfully  yours, 

G.  B.  AIRY. 


AT   GREENWICH   OBSERVATORY — 1 866  TO    1876.        273 

Consequent  on  Airy's  proposals  in  1866  for  the  introduc- 
tion of  new  physical  subjects  into  the  Senate-House  Ex- 
amination and  his  desire  that  the  large  number  of  questions 
set  in  Pure  Mathematics,  or  as  he  termed  it  "Useless 
Algebra,"  should  be  curtailed,  there  was  a  smart  and  in- 
teresting correspondence  between  him  and  Prof.  Cayley,  who 
was  the  great  exponent  and  advocate  of  Pure  Mathematics  at 
Cambridge.  Both  of  them  were  men  of  the  highest  mathe- 
matical powers,  but  diametrically  opposed  in  their  views  of 
the  use  of  Mathematics.  Airy  regarded  mathematics  as 
simply  a  useful  machine  for  the  solution  of  practical  problems 
and  arriving  at  practical  results.  He  had  a  great  respect  for 
Pure  Mathematics  and  all  the  processes  of  algebra,  so  far  as 
they  aided  him  to  solve  his  problems  and  to  arrive  at  useful 
results;  but  he  had  a  positive  aversion  to  mathematical 
investigations,  however  skilful  and  elaborate,  for  which  no 
immediate  practical  value  could  be  claimed.  Cayley  on  the 
contrary  regarded  mathematics  as  a  useful  exercise  for  the 
mind,  apart  from  any  immediate  practical  object,  and  he 
considered  that  the  general  command  of  mathematics  gained 
by  handling  abstruse  mathematical  investigations  (though 
barren  in  themselves)  would  be  valuable  for  whatever  pur- 
pose mathematics  might  be  required :  he  also  thought  it 
likely  that  his  researches  and  advances  in  the  field  of 
Pure  Mathematics  might  facilitate  the  solution  of  physical 
problems  and  tend  to  the  progress  of  the  practical  sciences. 
Their  different  views  on  this  subject  will  be  seen  from  the 
letters  that  follow : 

ROYAL  OBSERVATORY,  GREENWICH, 
LONDON,  S.E. 

1867,  Nov.  8. 
MY  DEAR  SIR, 

I  think  it  best  to  put  in  writing  the  purport  of  what  I 
have  said,  or  have  intended  to  say,  in  reference  to  the  Mathematical 
Studies  in  the  University. 

First,  I  will  remark  on  the  study  of  Partial  Differential  Equations. 
I  do  not  know  that  one  branch  of  Pure  Mathematics  can  be  con- 

A.  B.  18 


274  GEORGE   BIDDELL   AIRY. 

sidered  higher  than  another,  except  in  the  utility  of  the  power  which 
it  gives.  Measured  thus,  the  Partial  Differential  Equations  are  very 
useful  and  therefore  stand  very  high,  as  far  as  the  Second  Order. 
They  apply,  to  that  point,-  in  the  Jhost  important  way,  to  the  great 
problems  of  nature  concerning  //;>/<?,  and  infinite  division  of  ?natter, 
and  space :  and  are  worthy  of  the  most  careful  study.  Beyond  that 
Order  they  apply  to  nothing.  It  was  for  the  purppse  of  limiting  the 
study  to  the  Second  Order,  and  at  the  same  time  working  it  care- 
fully, philosophically,  and  practically,  up  to  that  point,  that  I  drew 
up  my  little  work. 

On  the  general  question  of  Mathematical  Studies,  I  will  first  give 
my  leading  ideas  on  what  I  may  call  the  moral  part.  I  think  that  a 
heavy  responsibility  rests  on  the  persons  who  influence  most  strongly 
the  course  of  education  in  the  University,  to  direct  that  course  in 
the  way  in  which  it  will  be  most  useful  to  the  students — in  the  two 
ways,  of  disciplining  their  powers  and  habits,  and  of  giving  them 
scientific  knowledge  of  the  highest  and  most  accurate  order  (applying 
to  the  phenomena  of  nature)  such  as  will  be  useful  to  them  through 
life.  I  do  not  think  that  the  mere  personal  taste  of  a  teacher  is 
sufficient  justification  for  a  special  course,  unless  it  has  been  adopted 
under  a  consideration  of  that  responsibility.  Now  I  can  say  for 
myself  that  I  have,  for  some  years,  inspected  the  examination 
papers,  and  have  considered  the  bearing  of  the  course  which  they 
imply  upon  the  education  of  the  student,  and  am  firmly  convinced 
that  as  regards  men  below  the  very  few  first — say  below  the  ten 
first — there  is  a  prodigious  loss  of  time  without  any  permanent  good 
whatever.  For  the  great  majority  of  men,  such  subjects  as  abstract 
Analytical  Geometry  perish  at  once.  With  men  like  Adams  and 
Stokes  they  remain,  and  are  advantageous ;  but  probably  there  is 
not  a  single  man  (beside  them)  of  their  respective  years  who 
remembers  a  bit,  or  who  if  he  remembers  them  has  the  leisure 
and  other  opportunities  of  applying  them. 

I  believe  on  the  other  hand  that  a  careful  selection  of  physical 
subjects  would  enable  the  University  to  communicate  to  its  students 
a  vast  amount  of  information  ;  of  accurate  kind  and  requiring  the 
most  logical  treatment ;  but  so  bearing  upon  the  natural  phenomena 
which  are  constantly  before  us  that  it  would  be  felt  by  every  student 
to  possess  a  real  value,  that  (from  that  circumstance)  it  would  dwell 
in  his  mind,  and  that  it  would  enable  him  to  correct  a  great  amount 
of  flimsy  education  in  the  country,  and,  so  far,  to  raise  the  national 
character. 


AT  GREENWICH   OBSERVATORY— 1 866  TO    1 8/6.        275 

The  consideration  of  the  education  of  the  reasoning  habits  sug- 
gests ideas  far  from  favourable  to  the  existing  course.  I  am  old 
enough  to  remember  the  time  of  mere  geometrical  processes,  and  I 
do  not  hesitate  to  say  that  for  the  cultivation  of  accurate  mental 
discipline  they  were  far  superior  to  the  operations  in  vogue  at  the 
present  day.  There  is  no  subject  in  the  world  more  favourable  to 
logical  habit  than  the  Differential  Calculus  in  all  its  branches  if 
logically  worked  in  its  elements :  and  I  think  that  its  applications  to 
various  physical  subjects,  compelling  from  time  to  time  an  attention 
to  the  elementary  grounds  of  the  Calculus,  would  be  far  more 
advantageous  to  that  logical  habit  than  the  simple  applications  to 
Pure  Equations  and  Pure  Algebraical  Geometry  now  occupying  so 
much  attention. 

I  am,  my  dear  Sir, 

Yours  very  truly, 

G.  B.  AIRY. 

Professor  Cayley. 


DEAR  SIR,' 

I  have  been  intending  to  answer  your  letter  of  the  8th 
November.  So  far  as  it  is  (if  at  all)  personal  to  myself,  I  would 
remark  that  the  statutory  duty  of  the  Sadlerian  Professor  is  that  he 
shall  explain  and  teach  the  principles  of  Pure  Mathematics  and 
apply  himself  to  the  advancement  of  the  Science. 

As  to  Partial  Differential  Equations,  they  are  "high"  as  being  an 
inverse  problem,  and  perhaps  the  most  difficult  inverse  problem  that 
has  been  dealt  with.  In  regard  to  the  limitation  of  them  to  the 
second  order,  whatever  other  reasons  exist  for  it,  there  is  also  the 
reason  that  the  theory  to  this  order  is  as  yet  so  incomplete  that  there 
is  no  inducement  to  go  beyond  it ;  there  could  hardly  be  a  more 
valuable  step  than  anything  which  would  give  a  notion  of  the  form 
of  the  general  integral  of  a  Partial  Differential  Equation  of  the 
second  order. 

I  cannot  but  differ  from  you  in  toto  as  to  the  educational  value 
of  Analytical  Geometry,  or  I  would  rather  say  of  Modern  Geometry 
generally.  It  appears  to  me  that  in  the  Physical  Sciences  depending 
on  Partial  Differential  Equations,  there  is  scarcely  anything  that  a 
student  can  do  for  himself: — he  finds  the  integral  of  the  ordinary 
equation  for  Sound — if  he  wishes  to  go  a  step  further  and  integrate 

1 8— 2 


2/6  GEORGE    BIDDELL   AIRY. 

the  non-linear  equation  ( —•)  ~^-  =  a2  -j^,  he  is  simply  unable  to  do 
\dxj   dt*         dx* 

so ;  and  so  in  other  cases  there  is  nothing  that  he  can  add  to  what 
he  finds  in  his  books.  'Whereas  Geometry  (of  course  to  an  intel- 
ligent student)  is  a  real  inductive  and  deductive  science  of  inex- 
haustible extent,  in  which  he  can  experiment  for  himself — the  very 
tracing  of  a  curve  from  its  equation  (and  still  more,  the  consideration 
of  the  cases  belonging  to  different  values  of  the  parameters)  is  the 
construction  of  a  theory  to  bind  together  the  facts — and  the  selec- 
tion of  a  curve  or  surface  proper  for  the  verification  of  any  general 
theorem  is  the  selection  of  an  experiment  in  proof  or  disproof  of  a 
theory. 

I  do  not  quite  understand  your  reference  to  Stokes  and  Adams, 
as  types  of  the  men  who  alone  retain  their  abstract  Analytical 
Geometry.  If  a  man  when  he  takes  his  degree  drops  mathematics, 
he  drops  geometry — but  if  not  I  think  for  the  above  reasons  that  he 
is  more  likely  to  go  on  with  it  than  with  almost  any  other  subject — 
and  any  mathematical  journal  will  shew  that  a  very  great  amount  of 
attention  is  in  fact  given  to  geometry.  And  the  subject  is  in  a  very 
high  degree  a  progressive  one ;  quite  as  much  as  to  Physics,  one 
may  apply  to  it  the  lines,  Yet  I  doubt  not  thro'  the  ages  one  in- 
creasing purpose  runs,  and  the  thoughts  of  men  are  widened  with  the 
progress  of  the  suns. 

I  remain,  dear  Sir, 

Yours  very  sincerely, 

A.  CAYLEY. 
CAMBRIDGE, 
6  Dec.,  1867. 


ROYAL  OBSERVATORY,  GREENWICH, 
LONDON,  S.E. 

1867,  December  9. 
MY  DEAR  SIR, 

I  have  received  with  much  pleasure  your  letter  of  Decem- 
ber 6.  In  this  University  discussion,  I  have  acted  only  in  public, 
and  have  not  made  private  communication  to  any  person  whatever 
till  required  to  do  so  by  private  letter  addressed  to  me.  Your  few 
words  in  Queens'  Hall  seemed  to  expect  a  little  reply. 


AT   GREENWICH   OBSERVATORY — 1 866   TO    1876.        277 

Now  as  to  the  Modern  Geometry.  With  your  praises  of  this 
science — as  to  the  room  for  extension  in  induction  and  deduction, 
&c. ;  and  with  your  facts — as  to  the  amount  of  space  which  it  occu- 
pies in  Mathematical  Journals ;  I  entirely  agree.  And  if  men,  after 
leaving  Cambridge,  were  designed  to  shut  themselves  up  in  a  cavern, 
they  could  have  nothing  better  for  their  subjective  amusement. 
They  might  have  other  things  as  good ;  enormous  complication  and 
probably  beautiful  investigation  might  be  found  in  varying  the  game 
of  billiards  with  novel  islands  on  a  newly  shaped  billiard  table.  But 
the  persons  who  devote  themselves  to  these  subjects  do  thereby 
separate  themselves  from  the  world.  (  They  make  no  step  towards 
natural  science  or  utilitarian  science,  the  two  subjects  which  the 
world  specially  desires.  The  world  could  go  on  as  well  without 
these  separatists. 

Now  if  these  persons  lived  only  for  themselves,  no  other 
person  would  have  any  title  to  question  or  remark  on  their 
devotion  to  this  barren  subject.  But  a  Cambridge  Examiner  is 
not  in  that  position.  The  University  is  a  national  body,  for 
education  of  young  men :  and  the  power  of  a  Cambridge  Examiner 
is  omnipotent  in  directing  the  education  of  the  young  men ; 
and  his  responsibility  to  the  cause  of  education  is  very  distinct 
and  very  strong.  And  the  question  for  him  to  consider  is — in  the 
sense  in  which  mathematical  education  is  desired  by  the  best  authori- 
ties in  the  nation,  is  the  course  taken  by  this  national  institution 
satisfactory  to  the  nation? 

I  express  my  belief  that  it  is  not.  satisfactory.  I  believe  that  many 
of  the  best  men  of  the  nation  consider  that  a  great  deal  of  time  is 
lost  on  subjects  which  they  esteem  as  puerile,  and  that  much  of  that 
time  might  be  employed  on  noble  and  useful  science. 

You  may  remember  that  the  Commissions  which  have  visited 
Cambridge  originated  in  a  Memorial  addressed  to  the  Government 
by  men  of  respected  scientific  character  :  Sabine  was  one,  and  I  may 
take  him  as  the  representative.  He  is  a  man  of  extensive  know- 
ledge of  the  application  of  mathematics  as  it  has  been  employed  for 
many  years  in  the  science  of  the  world ;  but  he  has  no  profundity  of 
science.  He,  as  I  believe,  desired  to  find  persons  who  could  enter 
accurately  into  mathematical  science,  and  naturally  looked  to  the 
Great  Mathematical  University;  but  he  must  have  been  much  dis- 
appointed. So  much  time  is  swallowed  up  by  the  forced  study  of 
the  Pure  Mathematics  that  it  is  not  easy  to  find  anybody  who  can 
really  enter  on  these  subjects  in  which  men  of  science  want  assist- 


2/8  GEORGE    BIDDELL  AIRY. 

ance.     And  so  Sabine  thought  that  the  Government  ought  to  inter- 
fere, probably  without  any  clear  idea  of  what  they  could  do. 

I  am,  my  dear  Sir, 

Yours  very  truly, 

G.    B.   AIRY. 

Professor  Cayley. 


DEAR  SIR, 

I  have  to  thank  you  for  your  last  letter.  I  do  not  think 
everything  should  be  subordinated  to  the  educational  element :  my 
idea  of  a  University  is  that  of  a  place  for  the  cultivation  of  all 
science.  Therefore  among  other  sciences  Pure  Mathematics;  in- 
cluding whatever  is  interesting  as  part  of  this  science.  I  am  bound 
therefore  to  admit  that  your  proposed  extension  of  the  problem  of 
billiards,  if  it  were  found  susceptible  of  interesting  mathematical 
developments,  would  be  a  fit  subject  of  study.  But  in  this  case  I  do 
not  think  the  problem  could  fairly  be  objected  to  as  puerile — a  more 
legitimate  objection  would  I  conceive  be  its  extreme  speciality.  But 
this  is  not  an  objection  that  can  be  brought  against  Modern  Geome- 
try as  a  whole :  in  regard  to  any  particular  parts  of  it  which  may 
appear  open  to  such  an  objection,  the  question  is  whether  they  are 
or  are  not,  for  their  own  sakes,  or  their  bearing  upon  other  parts  of 
the  science  to  which  they  belong,  worthy  of  being  entered  upon  and 
pursued. 

But  admitting  (as  I  do  not)  that  Pure  Mathematics  are  only  to 
be  studied  with  a  view  to  Natural  and  Physical  Science,  the  question 
still  arises  how  are  they  best  to  be  studied  in  that  view.  I  assume 
and  admit  that  as  to  a  large  part  of  Modern  Geometry  and  of  the 
Theory  of  Numbers,  there  is  no  present  probability  that  these  will 
find  any  physical  applications.  But  among  the  remaining  parts  of 
Pure  Mathematics  we  have  the  theory  of  Elliptic  Functions  and  of 
the  Jacobian  and  Abelian  Functions,  and  the  theory  of  Differential 
Equations,  including  of  course  Partial  Differential  Equations.  Now 
taking  for  instance  the  problem  of  three  bodies — unless  this  is  to  be 
gone  on  with  by  the  mere  improvement  in  detail  of  the  present 
approximate  methods — it  is  at  least  conceivable  that  the  future  treat- 
ment of  it  will  be  in  the  direction  of  the  problem  of  two  fixed  centres, 
by  means  of  elliptic  functions,  &c. ;  and  that  the  discovery  will  be 
made  not  by  searching  for  it  directly  with  the  mathematical  resources 


AT   GREENWICH   OBSERVATORY — 1 866  TO    1876.        279 

now  at  our  command,  but  by  "prospecting"  for  it  in  the  field  of 
these  functions.  Even  improvements  in  the  existing  methods  are 
more  likely  to  arise  from  a  study  of  differential  equations  in  general 
than  from  a  special  one  of  the  equations  of  the  particular  problem  : 
the  materials  for  such  improvements  which  exist  in  the  writings  of 
Hamilton,  Jacobi,  Bertrand,  and  Bour,  have  certainly  so  arisen. 
And  the  like  remarks  would  apply  to  the  physical  problems  which 
depend  on  Partial  Differential  Equations. 

I  think  that  the  course  of  mathematical  study  at  the  University 
is  likely  to  be  a  better  one  if  regulated  with  a  view  to  the  cultivation 
of  Science,  as  if  for  its  own  sake,  rather  than  directly  upon  considera- 
tions of  what  is  educationally  best  (I  mean  that  the  best  educational 
course  will  be  so  obtained),  and  that  we  have  thus  a  justification  for 
a  thorough  study  of  Pure  Mathematics.  In  my  own  limited  expe- 
rience of  examinations,  the  fault  which  I  find  with  the  men  is  a  want 
of  analytical  power,  and  that  whatever  else  may  have  been  in  defect 
Pure  Mathematics  has  certainly  not  been  in  excess. 

I  remain,  dear  Sir, 

Yours  sincerely, 

A.    CAYLEY. 

CAMBRIDGE, 

loth  Dec.,  1867. 


1867,  December  17. 
MY  DEAR  SIR, 

Since  receiving  your  letter  of  Qth  I  positively  have  not 
had  time  to  express  the  single  remark  which  I  proposed  to  make 
on  it. 

You  state  your  idea  that  the  educational  element  ought  not  to  be 
the  predominating  element  in  the  University.  "  I  do  not  think  that 
every  thing  should  be  subordinated  to  the  educational  element."  I 
cannot  conceal  my  surprise  at  this  sentiment.  Assuredly  the  founders 
of  the  Colleges  intended  them  for  education  (so  far  as  they  apply  to 
persons  in  statu  pupillari),  the  statutes  of  the  University  and  the 
Colleges  are  framed  for  education,  and  fathers  send  their  sons  to  the 
University  for  education.  If  I  had  not  had  your  words  before  me,  I 
should  have  said  that  it  is  impossible  to  doubt  this. 

It  is  much  to  be  desired  that  Professors  and  others  who  exercise 
no  control  by  force  should  take  every  method,  not  only  of  promoting 


28O  GEORGE   BIDDELL   AIRY. 

science  in  themselves,  but  also  of  placing  the  promoted  science 
before  students :  and  it  is  much  to  be  desired  that  students  who 
have  passed  the  compulsory  curriculum  should  be  encouraged  to 
proceed  into  the  novelties  which  will  be  most  agreeable  to  them. 
But  this  is  a  totally  different  thing  -from  using  the  Compulsory  Force 
of  Examination  to  drive  students  in  paths  traced  only  by  the  taste  of 
the  examiner.  For  them,  I  conceive  the  obligation  to  the  nation 
and  the  duty  to  follow  the  national  sense  on  education  (as  far  as  it 
can  be  gathered  from  its  best  representatives)  to  be  undoubted ;  and 
to  be,  in  the  intensity  of  the  obligation  and  duty,  most  serious. 

I  am,  my  dear  Sir, 

Yours  very  truly, 

G.    B.   AIRY. 
Professor  Cayley. 


1868 

"In  the  South-East  Dome,  the  alteration  proposed  last 
year  for  rendering  the  building  fire-proof  had  been  completely 
carried  out  The  middle  room,  which  was  to  be  appropriated 
to  Chronometers,  was  being  fitted  up  accordingly. — From  the 
Report  it  appears  that  'our  subterranean  telegraph  wires 
were  all  broken  by  one  blow,  from  an  accident  in  the  Metro- 
politan Drainage  Works  on  Croom's  Hill,  but  were  speedily 
repaired.' — In  my  office  as  Chairman  of  successive  Commis- 
sions on  Standards,  I  had  collected  a  number  of  Standards, 
some  of  great  historical  value  (as  Ramsden's  and  Roy's 
Standards  of  Length,  Kater's  Scale-beam  for  weighing  great 
weights,  and  others),  &c.  These  have  been  transferred  to  the 
newly-created  Standards  Department  of  the  Board  of  Trade." 
— In  the  Report  is  given  a  detailed  account  of  the  system  of 
preserving  and  arranging  the  manuscripts  and  correspondence 
of  the  Observatory,  which  was  always  regarded  by  Airy  as  a 
matter  of  the  first  importance. — From  a  careful  discussion  of 
j  the  results  of  observation  Mr  Stone  had  concluded  that  the 
refractions  ought  to  be  diminished,  '  Relying  on  this,  we 


AT   GREENWICH   OBSERVATORY— 1 866   TO    l8/6.        281 

have  now  computed  our  mean  refractions  by  diminishing 
those  of  Bessel's  Fundamenta  in  the  proportion  of  I  to 
0-99797.' — The  Magnetometer-Indications  for  the  period 
1858 — 1863  had  been  reduced  and  discussed,  with  remarkable 
results.  It  is  inferred  that  magnetic  disturbances,  both  solar 
and  lunar,  are  produced  mediately  by  the  Earth,  and  that  the 
Earth  in  periods  of  several  years  undergoes  changes  which  fit 
it  and  unfit  it  for  exercising  a  powerful  mediate  action. — The 
Earth-current  records  had  been  reduced,  and  the  magnetic 
effect  which  the  currents  would  produce  had  been  computed. 
The  result  was,  that  the  agreement  between  the  magnetic 
effects  so  computed  and  the  magnetic  disturbances  really 
recorded  by  the  magnetometers  was  such  as  to  leave  no 
doubt  on  the  general  validity  of  the  explanation  of  the  great 
storm-disturbances  of  the  magnets  as  consequences  of  the 
galvanic  currents  through  the  earth. — Referring  to  the  diffi- 
culty experienced  in  making  the  meteorological  observations 
practically  available  the  Report  states  thus :  '  The  want  of 
Meteorology,  at  the  present  time,  is  principally  in  suggestive 
theory.' — In  this  year  Airy  communicated  to  the  Royal 
Astronomical  Society  a  Paper  '  On  the  Preparatory  Arrange- 
ments for  the  Observation  of  the  Transits  of  Venus  1874  and 
1882' :  this  subject  was  now  well  in  hand. — The  First  Report 
of  the  Commissioners  (of  whom  he  was  Chairman)  appointed 
to  enquire  into  the  condition  of  the  Exchequer  Standards 
was  printed  :  this  business  took  up  much  time. — He  was  in 
this  year  much  engaged  on  the  Coinage  Commission. 

Of  private  history :  There  was  the  usual  winter  visit  to 
Playford,  and  a  short  visit  to  Cambridge  in  June. — From 
about  Aug.  ist  to  Sept.  3rd  he  was  travelling  in  Switzerland 
with  his  youngest  son  and  his  two  youngest  daughters.  In 
the  course  of  this  journey  they  visited  Zermatt.  There  had 
been  much  rain,  the  rivers  were  greatly  flooded,  and  much 
mischief  was  done  to  the  roads.  During  the  journey  from 
Visp  to  Zermatt,  near  St  Nicholas,  in  a  steep  part  of  the 
gorge,  a  large  stone  rolled  from  the  cliffs  and  knocked  their 


282  GEORGE  BIDDELL  AIRY. 

baggage  horse  over  the  lower  precipice,  a  fall  of  several 
hundred  feet.  The  packages  were  all  burst,  and  many  things 
were  lost,  but  a  good  deal  was  recovered  by  men  suspended 
by  ropes. 

In  this  year  also  Airy  was  busy  with  the  subject  of 
University  Examination,  which  in  previous  years  had  occu- 
pied so  much  of  his  attention,  as  will  be  seen  from  the  follow- 
ing letters : 

ROYAL  OBSERVATORY,  GREENWICH, 
LONDON,  S.E. 

1868,  March  12. 
MY  DEAR  MASTER, 

I  have  had  the  pleasure  of  corresponding  with  you  on 
matters  of  University  Examination  so  frequently  that  I  at  once  turn 
to  you  as  the  proper  person  to  whom  I  may  address  any  remarks  on 
that  important  subject. 

Circumstances  have  enabled  me  lately  to  obtain  private  informa- 
tion of  a  most  accurate  kind  on  the  late  Mathematical  Tripos :  and 
among  other  things,  I  have  received  a  statement  of  every  individual 
question  answered  or  partly  answered  by  five  honour-men.  I  have 
collected  the  numbers  of  these  in  a  small  table  which  I  enclose. 

I  am  struck  with  the  almost  nugatory  character  of  the  five  days' 
honour  examination  as  applied  to  Senior  Optimes,  and  I  do  not 
doubt  that  it  is  totally  nugatory  as  applied  to  Junior  Optimes.  It 
appears  to  me  that,  for  all  that  depends  on  these  days,  the  rank  of 
the  Optimes  is  mere  matter  of  chance. 

In  the  examinations  of  the  Civil  Service,  the  whole  number  of 
marks  is  published,  and  also  the  number  of  marks  gained  by  each 
candidate.  I  have  none  of  their  papers  at  hand,  but  my  impression 
is  that  the  lowest  candidates  make  about  i  in  3 ;  and  the  fair  candi- 
dates about  2  in  3,  instead  of  i  in  10  or  i  in  13  as  our  good  Senior 
Optimes. 

I  am,  my  dear  Master, 

Very  truly  yours, 

G.    B.    AIRY. 
The  Rev.  Dr  Cookson, 

Master  of  St  Peter's  College, 


AT   GREENWICH   OBSERVATORY — 1 866   TO    1 8/6.        283 

The  Table  referred  to  in  the  above  letter  is  as  follows : 

Number  of  Questions,  and  numbers  of  Answers  to  Questions  as 
given  by  several  Wranglers  and  Senior  Optimes,  in  the  Examination 
of  Mathematical  Tripos  for  Honours,  1868,  January  13,  14,  15, 
16,  17. 

Number  of  Questions  and  Riders  in  the  Printed  Papers. 

Questions.  Riders.  Aggregate. 

In  the  10  Papers  of  the  5  days  123  101  224 

NUMBER  OF  QUESTIONS  AND  RIDERS  ANSWERED. 


By  a  Wrangler,  between  the  ist  and 
7th 

Questions. 

6o4 

Riders. 

2=1 

Aggregate. 

QK 

i  in  2*36 

By  a  Wrangler,  between  the  i2th 
and  2  2  nd  

48i 

12* 

6l 

i  in  3*68 

By  a  Wrangler,  between  the  2  2nd 
and  32nd  

36 

12* 

48i 

i  in  4*62 

By  a  Sen.  Opt.  between  the  ist  and 
loth 

171 

•22* 

i  in  Q*o5 

By  a  Sen.  Opt.  between  the  roth  and 

2Oth  

14! 

2 

16* 

i  in  13*60 

G.    B.   AIRY. 


1868,  March  12. 


ST  PETER'S  COLLEGE  LODGE,  CAMBRIDGE, 

March  i$th,  1868. 
MY  DEAR  SIR, 

I  am  much  obliged  by  your  letter  and  enclosed  paper. 

Any  thing  done  in  the  last  five  days  by  a  Junior  Optime  only 
shews  (generally)  that  he  has  been  employing  some  of  his  time 
mischievously ,  for  he  must  have  been  working  at  subjects  which  he  is 
quite  unable  to  master  or  cramming  them  by  heart  on  the  chance  of 
meeting  with  a  stray  question  which  he  may  answer. 

The  chief  part  of  the  Senior  Optimes  are  in  something  of  the 
same  situation. 

I  think  that  the  proposed  addition  of  a  day  to  the  first  part  of 
the  Examination,  in  which  "easy  questions  in  physical  subjects" 
may  be  set,  is,  on  this  account,  a  great  improvement. 

Our  new  Scheme  comes  on  for  discussion  on  Friday  next, 
March  20,  at  2  p.m.  in  the  Arts  School.  It  is  much  opposed  by 


284  GEORGE   BIDDELL  AIRY. 

private  tutors,  examiners  and  others,  and  may  possibly  be  thrown  out 
in  the  Senate  this  year,  though  I  hope  that  with  a  little  patience  it 
may  be  carried,  in  an  unmutilated  form,  eventually. 

The  enclosed  Reporton  the  Srm'th's  Prize  Examination  will  be 
discussed  at  the  same  time. 

I  will  consider  what  is  best  to  be  done  on  the  subject  to  which 
your  note  refers,  without  delay.  With  many  thanks, 

I  am, 

Very  faithfully  yours, 

H.   W.    COOKSON. 

The  Astronomer  Royal. 


In  this  year  certain  Members  of  the  Senate  of  the  Uni- 
versity of  Cambridge  petitioned  Parliament  against  the  aboli- 
tion of  religious  declarations  required  of  persons  admitted  to 
Fellowships  or  proceeding  to  the  degree  of  M.A.  The  docu- 
ment was  sent  to  Airy  for  his  signature,  and  his  reply  was  as 
follows  : 

ROYAL  OBSERVATORY,  GREENWICH, 
LONDON,  S.E. 

1868,  March  18. 
MY  DEAR  SIR, 

Though  I  sympathize  to  a  great  extent  with  the 
prayer  of  the  petition  to  Parliament  which  you  sent  to  me  yesterday, 
and  assent  to  most  of  the  reasons,  I  do  not  attach  my  signature  to 
it,  for  the  following  considerations  : 

1.  I  understand,  from  the  introductory  clause,  and  from  the 
unqualified  character  of  the  phrase  "any  such  measures"  in  the 
second  clause,  that  the  petition  objects  to  granting  the  M.A.  degree 
without  religious  declaration.     I  do  not  see  any  adequate  necessity 
for  this  objection,  and  I  cannot  join  in  it. 

2.  It  appears  to  me  that  the  Colleges  were  intended  for  two 
collateral   objects  : — instruction  by  part  of  the   Fellows,  on  a  re- 
ligious basis ;   and   support  of  certain   Fellows   for   scientific  pur- 
poses, without  the  same  ostentatious  connection  with  religion.     I 
like  this  spirit  well,  and  should  be  glad  to  maintain  it. 

3.  I  therefore  think  (as  I  have  publicly  stated  before)  that  the 
Master  of  the  College  ought  to  be  in  holy  orders ;  and  so  ought 


AT   GREENWICH   OBSERVATORY — 1 866   TO    1876.        285 


those  of  the  Fellows  who  may  be  expected  to  be  usually  resident 
and  to  take  continuous  part  in  the  instruction.  But  there  are  many 
who,  upon  taking  a  fellowship,  at  once  lay  aside  all  thoughts  of 
this  :  and  I  think  that  such  persons  ought  not  to  be  trammelled  with 
declarations. 

4.  My  modification  of  existing  regulations,  if  it  once  got  into 
shape,  would  I  dare  say  be  but  a  small  fraction  of  that  proposed 
by  the  "  measures  in  contemplation."  Still  I  do  not  like  to  join  in 
unqualified  resistance  to  interference  in  the  affairs  of  the  Established 
Colleges,  with  that  generality  of  opposition  to  interference  which  the 
petition  seems  to  intimate. 

I  agree  with  articles  3,  4,  and  5  ;  and  I  am  pleased  with  the 
graceful  allusion  in  article  4  to  the  assistance  which  has  been  ren- 
dered by  the  Colleges,  and  by  none  perhaps  so  honourably  as 
Trinity,  to  the  parishes  connected  with  it.  And  I  could  much 
wish  that  the  spirit  of  3  and  5  could  be  carried  out,  with  some 
concession  to  my  ideas  in  my  paragraph  3,  above. 

I  am,  my  dear  Sir, 

Yours  very  truly, 

G.  B.  AIRY. 
Rev.  Dr  Lightfoot. 


1869 

From  the  Report  to  the  Board  of  Visitors  it  appears  that 
application  had  been  made  for  an  extension  of  the  grounds 
of  the  Observatory  to  a  distance  of  100  feet  south  of  the 
Magnetic  Ground,  and  that  a  Warrant  for  the  annexation 
of  this  space  was  signed  on  1868,  Dec.  8.  The  new  Depot 
for  the  Printed  Productions  of  the  Observatory  had  been 
transferred  to  its  position  in  the  new  ground,  and  the  founda- 
tions for  the  Great  Shed  were  completed. — "  The  courses  of 
our  wires  for  the  registration  of  spontaneous  terrestrial  gal- 
vanic currents  have  been  entirely  changed.  The  lines  to 
Croydon  and  Deptford  are  abandoned  ;  and  for  these  are 
substituted,  a  line  from  Angerstein  Wharf  to  Lady  Well 
Station,  and  a  line  from  North  Kent  Junction  to  Morden 


286  GEORGE   BIDDELL  AIRY. 

College  Tunnel.  At  each  of  these  points  the  communica- 
tion with  Earth  is  made  by  a  copper  plate  2  feet  square. 
The  straight  line  connecting  the  extreme  points  of  the  first 
station  intersects  that  connecting  the  two  points  of  the 
second  station,  nearly  at  right  angles,  and  at  little  distance 
from  the  Observatory. — The  question  of  dependence  of  the 
measurable  amount  of  sidereal  aberration  upon  the  thickness 
of  glass  or  other  transparent  material  in  the  telescope  (a 
question  which  involves,  theoretically,  one  of  the  most  deli- 
cate points  in  the  Undulatory  Theory  of  Light)  has  lately 
been  agitated  on  the  Continent  with  much  earnestness.  I 
have  calculated  the  curvatures  of  the  lenses  of  crown  and 
flint  glass  (the  flint  being  exterior)  for  correcting  spherical 
and  chromatic  aberration  in  a  telescope  whose  tube  is  filled 
with  water,  and  have  instructed  Mr  Simms  to  proceed  with 
the  preparation  of  an  instrument  carrying  such  a  telescope. 
I  have  not  finally  decided  whether  to  rely  on  Zenith-distances 
of  7  Draconis  or  on  right-ascensions  of  Polaris.  In  any  form 
the  experiment  will  probably  be  troublesome. — The  transit 
of  Mercury  on  1868,  Nov.  4th,  was  observed  by  six  ob- 
servers. The  atmospheric  conditions  were  favourable;  and 
the  singular  appearances  usually  presented  in  a  planetary 
transit  were  well  seen. — Mr  Stone  has  attached  to  the  South- 
East  Equatoreal  a  thermo-multiplier,  with  the  view  of  ex- 
amining whether  heat  radiating  from  the  principal  stars  can 
be  made  sensible  in  our  instruments.  The  results  hitherto 
obtained  are  encouraging,  but  they  shew  clearly  that  it  is 
vain  to  attempt  this  enquiry  except  in  the  most  superb 
weather ;  and  there  has  not  been  a  night  deserving  that 
epithet  for  some  months  past. — The  preparations  for  ob- 
serving the  Transits  of  Venus  were  now  begun  in  earnest. 
I  had  come  to  the  conclusion,  that  after  every  reliance  was 
placed  on  foreign  and  colonial  observatories,  it  would  be 
necessary  for  the  British  Government  to  undertake  the 
equipment  of  five  or  six  temporary  stations.  On  Feb.  I5th 
I  sent  a  pamphlet  on  the  subject  to  Mr  Childers  (First 


AT   GREENWICH   OBSERVATORY — 1 866   TO    1876.        287 

Lord  of  Admiralty),  and  in  April  I  wrote  to  the  Secretary, 
asking  authority  for  the  purchase  of  instruments.  On  June 
22nd  authority  is  given  to  me  for  the  instruments:  the 
Treasury  assent  to  £10,500.  On  August  9th  I  had  pur- 
chased 3  equatoreals. — I  have  given  a  short  course  of  Lec- 
tures in  the  University  of  Cambridge  on  the  subject  of 
Magnetism,  with  the  view  of  introducing  that  important 
physical  science  into  the  studies  of  the  University.  The 
want  of  books  available  to  Students,  and  the  novelty  of  the 
subject,  made  the  preparation  more  laborious  than  the  dura- 
tion of  the  lectures  would  seem  to  imply." — In  this  year 
there  was  much  work  on  the  Standards  Commission,  chiefly 
regarding  the  suggested  abolition  of  Troy  Weight,  and 
several  Papers  on  the  subject  were  prepared  by  Airy. — 
He  also  wrote  a  long  and  careful  description  of  the  Great 
Equatoreal  at  Greenwich. 

Of  private  history:  There  was  the  usual  visit  to  Playford 
in  the  winter.  Mrs  Airy  was  now  becoming  feebler,  and 
did  not  now  leave  Greenwich :  since  April  of  this  year  her 
letters  were  written  in  pencil,  and  with  difficulty,  but  she 
still  made  great  efforts  to  keep  up  the  accustomed  corre- 
spondence.— In  April  Airy  went  to  Cambridge  to  deliver 
his  lectures  on  magnetism  to  the  undergraduates :  the  fol- 
lowing passage  occurs  in  one  of  his  letters  at  this  time : 
"  I  have  a  mighty  attendance  (there  were  147  names  on 
my  board  yesterday),  and,  though  the  room  is  large  with 
plenty  of  benches,  I  have  been  obliged  to  bring  in  some 
chairs.  The  men  are  exceedingly  attentive,  and  when  I 
look  up  I  am  quite  struck  to  see  the  number  of  faces 
staring  into  mine.  I  go  at  12,  and  find  men  at  the  room 
copying  from  my  big  papers :  I  lecture  from  I  to  2,  and 
stop  till  after  3,  and  through  the  last  hour  some  men  are 
talking  to  me  and  others  are  copying  from  the  papers ; 
and  I  usually  leave  some  men  still  at  work.  The  men 
applaud  and  shew  their  respect  very  gracefully.  Tfiere 
are  present  some  two  or  three  persons  who  attended  my 


288  GEORGE   BIDDELL   AIRY. 

former  lectures,  and  they  say  that  I  lecture  exactly  as  I 
did  formerly.  One  of  my  attendants  is  a  man  that  they 
say  cannot,  from  years  and  infirmity  and  habit,  be  induced 
to  go  anywhere  else:  'Dr  Atffrhdall,  the  Master  of  Em- 
manuel. I  find  that  some  of  my  old  lecturing  habits  come 
again  on  me.  I  drink  a  great  deal  of  cold  water,  and  am 
very  glad  to  go  to  bed  early." — From  June  loth — 3Oth  he 
was  travelling  in  Scotland,  and  staying  at  Barrow  House 
near  Keswick  (the  residence  of  Mr  Langton),  with  his  son 
Hubert. — Subsequently,  from  Aug.  i/th  to  3ist,  he  was 
again  in  the  Lake  District,  with  his  daughter  Christabel, 
and  was  joined  there  by  his  son  Hubert  on  the  24th.  The 
first  part  of  the  time  was  spent  at  Tarn  Bank,  near  Carlisle, 
the  residence  of  Mr  Isaac  Fletcher,  M.P.  From  thence  he 
made  several  expeditions,  especially  to  Barrow  in  Furness 
and  Seascale,  where  he  witnessed  with  great  interest  the 
Bessemer  process  of  making  steel.  From  Barrow  House  he 
made  continual  excursions  among  the  Cumberland  moun- 
tains, which  he  knew  so  well. 


1870 

"In  this  year  Mr  Stone,  the  First  Assistant,  was  appointed 
to  the  Cape  of  Good  Hope  Observatory,  and  resigned  his 
post  of  First  Assistant.  Mr  Christie  was  appointed  in  his 
place. — From  the  Report  to  the  Visitors  it  appears  that  'A 
few  months  since  we  were  annoyed  by  a  failure  in  the 
illumination  of  the  field  of  view  of  the  Transit  Circle.  The 
reflector  was  cleaned,  but  in  vain  ;  at  last  it  was  discovered 
that  one  of  the  lenses  (the  convex  lens)  of  the  combination 
which  forms  the  object-glass  of  a  Reversed  Telescope  in  the 
interior  of  the  Transit-axis,  and  through  which  all  illumi- 
nating light  must  pass,  had  become  so  corroded  as  to  be 
almost  opaque.'  —  The  South-East  Equatoreal  has  been 
partly  occupied  with  the  thermo-multiplier  employed  by  Mr 
Stone  for  the  measure  of  heat  radiating  from  the  principal 


AT  GREENWICH  OBSERVATORY— 1 866  TO    1876.        289 

stars.  Mr  Stone's  results  for  the  radiation  from  Arcturus  and 
a  Lyrae  appear  to  be  incontrovertible,  and  to  give  bases  for 
distinct  numerical  estimation  of  the  radiant  heat  of  these 
stars. — In  my  last  Report  I  alluded  to  a  proposed  systematic 
reduction  of  the  meteorological  observations  during  the  whole 
time  of  their  efficient  self-registration.  Having  received  from 
the  Admiralty  the  funds  necessary  for  immediate  operations, 
I  have  commenced  with  the  photographic  registers  of  the 
thermometers,  dry-bulb  and  wet-bulb,  from  1848  to  1868. — 
Our  chronometer-room  contains  at  present  219  chronometers^ 
including  37  chronometers  which  have  been  placed  here  by 
chronometer-makers  as  competing  for  the  honorary  reputation 
and  the  pecuniary  advantages  to  be  derived  from  success  in 
the  half-year's  trial  to  which  they  are  subjected.  I  take  this 
opportunity  of  stating  that  I  have  uniformly  advocated  the 
policy  of  offering  good  prices  for  the  chronometers  of  great 
excellence,  and  that  I  have  given  much  attention  to  the 
decision  on  their  merits ;  and  I  am  convinced  that  this 
system  has  greatly  contributed  to  the  remarkably  steady 
improvement  in  the  performance  of  chronometers.  In  the 
trial  which  terminated  in  August  1869,  the  best  chronometers 
(taking  as  usual  the  average  of  the  first  six)  were  superior  in 
merit  to  those  of  any  preceding  year. — With  the  funds  placed 
at  my  disposal  for  the  Transit  of  Venus  1874  I  purchased 
three  6-inch  equatoreals,  and  have  ordered  two :  I  have  also 
ordered  altazimuths  (with  accurate  vertical  circles  only),  and 
clocks  sufficient,  as  I  expect,  to  equip  five  stations.  For 
methods  of  observation,  I  rely  generally  on  the  simple  eye- 
observation,  possibly  relieved  of  some  of  its  uncertainty  by  the 
use  of  my  colour-correcting  eyepiece.  But  active  discussion 
has  taken  place  on  the  feasibility  of  using  photographic  and 
spectroscopic  methods ;  and  it  will  not  be  easy  for  some  time 
to  announce  that  the  plan  of  observations  is  settled. — There 
can  be  no  doubt,  I  imagine,  that  the  first  and  necessary  duty 
of  the  Royal  Observatory  is  to  maintain  its  place  well  as  an 
Observing  Establishment  ;  and  that  this  must  be  secured,  at 
A.  B.  19 


290  GEORGE   BIDDELL  AIRY. 

whatever  sacrifice,  if  necessary,  of  other  pursuits.  Still  the 
question  has  not  unfrequently  presented  itself  to  me,  whether 
the  duties  to  which  I  allude  have  not,  by  force  of  circum- 
stances, become  too  exclusive^  and  whether  the  cause  of 
Science  might  not  gain  if,  as  in  the  Imperial  Observatory  of 
Paris  for  instance,  the  higher  branches  of  mathematical 
physics  should  not  take  their  place  by  the  side  of  Obser- 
vatory routine.  I  have  often  felt  the  desire  practically  to 
refresh  my  acquaintance  with  what  were  once  favourite 
subjects :  Lunar  Theory  and  Physical  Optics.  But  I  do  not 
at  present  clearly  see  how  I  can  enter  upon  them  with  that 
degree  of  freedom  of  thought  which  is  necessary  for  success 
in  abstruse  investigations." 

Of  private  history :  There  was  a  longer  visit  than  usual 
to  Playford,  lasting  till  Jan.  27th. — In  April  he  made  a  short 
excursion  (of  less  than  a  week)  with  his  son  Hubert  to 
Monmouth,  &c. — From  June  I4th  to  July  2nd  he  was  staying 
at  Barrow  House,  near  Keswick,  with  his  son  Hubert  :  during 
this  time  he  was  much  troubled  with  a  painful  skin-irritation 
of  his  leg  and  back,  which  lasted  in  some  degree  for  a  long 
time  afterwards. — From  Sept.  25th  to  Oct.  6th  he  made  an 
excursion  with  his  daughter  Christabel  to  Scarborough, 
Whitby,  &c.,  and  again  spent  a  few  days  at  Barrow 
House. 


1871 

"  In  April  1870  the  Assistants  had  applied  for  an  increase 
of  salary,  a  request  which  I  had  urged  strongly  upon  the 
Admiralty.  On  Jan.  27  of  this  year  the  Admiralty  answered 
that,  on  account  of  Mr  Childers's  illness,  the  consideration 
must  be  deferred  to  next  year !  The  Assistants  wrote 
bitterly  to  me :  and  with  my  sanction  they  wrote  to  the 
First  Lord.  On  Jan.  3ist  I  requested  an  interview  with  Mr 
Baxter  (secretary  of  the  Admiralty),  and  saw  him  on 
Feb.  3rd,  when  I  obtained  his  consent  to  an  addition  of 


AT  GREENWICH   OBSERVATORY— 1 866  TO    1876.        291 

,£530.  There  was  still  a  difficulty  with  the  Treasury,  but 
on  June  27th  the  liberal  scale  was  allowed. — Experiments 
made  by  Mr  Stone  shew  clearly  that  a  local  elevation,  like 
that  of  the  Royal  Observatory  on  the  hill  of  Greenwich  Park, 
has  no  tendency  to  diminish  the  effect  of  railway  tremors. — 
The  correction  for  level  error  in  the  Transit  Circle  having 
become  inconveniently  large,  a  sheet  of  very  thin  paper, 
Y|Q  inch  in  thickness,  was  placed  under  the  eastern  Y,  which 
was  raised  from  its  bed  for  the  purpose.  The  mean  annual 
value  of  the  level-error  appears  to  be  now  sensibly  zero. — As 
the  siege  and  war  operations  in  Paris  seriously  interfered 
with  the  observations  of  small  planets  made  at  the  Paris 
Observatory,  observations  of  them  were  continued  at  Green- 
wich throughout  each  entire  lunation  during  the  investment 
of  the  city. — The  new  Water-Telescope  has  been  got  into 
working  order,  and  performs  most  satisfactorily.  Obser- 
vations of  7  Draconis  have  been  made  with  it,  when  the  star 
passed  between  2Oh-  and  I7h-,  with  some  observations  for 
adjustment  at  a  still  more  advanced  time.  As  the  astro- 
nomical latitude  of  the  place  of  observation  is  not  known,  the 
bearing  of  these  observations  on  the  question  of  aberration 
cannot  be  certainly  pronounced  until  the  autumn  observations 
shall  have  been  made ;  but  supposing  the  geodetic  latitude 
to  be  accordant  with  the  astronomical  latitude,  the  result  for 
aberration  appears  to  be  sensibly  the  same  as  with  ordinary 
telescopes. — Several  years  since,  I  prepared  a  barometer,  by 
which  the  barometric  fluctuations  were  enlarged,  for  the 
information  of  the  public ;  its  indications  are  exhibited  on  the 
wall,  near  to  the  entrance  gate  of  the  Observatory.  A  card 
is  now  also  exhibited,  in  a  glass  case  near  the  public 
barometer,  giving  the  highest  and  lowest  readings  of  the 
thermometer  in  the  preceding  twenty-four  hours. — Those 
who  have  given  attention  to  the  history  of  Terrestrial 
Magnetism  are  aware  that  Halley's  Magnetic  Chart  is  very 
frequently  cited  ;  but  I  could  not  learn  that  any  person,  at 
least  in  modern  times,  had  seen  it.  At  last  I  discovered  a 

19 — 2 


2Q2  GEORGE   BIDDELL  AIRY. 

copy  in  the  library  of  the  British  Museum,  and  have  been 
allowed  to  take  copies  by  photolithography.  These  are 
appended  to  the  Magnetical  and  Meteorological  Volume  for 
1869. — The  trials  and  certificates  of  hand-telescopes  for  the 
use  of  the  Royal  Navy  have  lately  been  so  frequent  that  they 
almost  become  a  regular  part  of  the  work  of  the  Observatory. 
I  may  state  here  that  by  availing  myself  of  a  theory  of 
eyepieces  which  I  published  long  since  in  the  Cambridge 
Transactions,  I  have  been  able  to  effect  a  considerable  im- 
provement in  the  telescopes  furnished  to  the  Admiralty. — 
The  occurrence  of  the  Total  Eclipse  of  the  Sun  in  December 
last  has  brought  much  labour  upon  the  Observatory.  As 
regards  the  assistants  and  computers,  the  actual  observation 
on  a  complicated  plan  with  the  Great  Equatoreal  (a  plan  for 
which  few  equatoreals  are  sufficiently  steady,  but  which  when 
properly  carried  out  gives  a  most  complete  solution  of  the 
geometrical  problem)  has  required,  in  observation  and  in 
computation,  a  large  expenditure  of  time. — My  preparations 
for  the  Transit  of  Venus  have  respect  only  to  eye-observation 
of  contact  of  limbs.  With  all  the  liabilities  and  defects  to 
which  it  is  subject,  this  method  possesses  the  inestimable 
advantage  of  placing  no  reliance  on  instrumental  scales.  I 
hope  that  the  error  of  observation  may  not  exceed  four 
seconds  of  time,  corresponding  to  about  ex  13"  of  arc.  I  shall 
be  very  glad  to  see,  in  a  detailed  form,  a  plan  for  making  the 
proper  measures  by  heliometric  or  photographic  apparatus; 
and  should  take  great  interest  in  combining  these  with  the 
eye-observations,  if  my  selected  stations  can  be  made  avail- 
able. But  my  present  impression  is  one  of  doubt  on  the 
certainty  of  equality  of  parts  in  the  scale  employed.  An 
error  depending  on  this  cause  could  not  be  diminished  by 
any  repetition  of  observations." — After  referring  to  the  desira- 
bility of  vigorously  prosecuting  the  Meteorological  Reductions 
(already  begun)  and  of  discussing  the  Magnetic  Observations, 
the  Report  concludes  thus :  "  There  is  another  consideration 
which  very  often  presents  itself  to  my  mind;  the  waste  of 


AT   GREENWICH   OBSERVATORY — 1 866  TO    1876.        293 

labour  in  the  repetition  of  observations  at  different  observa- 
tories  I  think  that  this  consideration  ought  not  to  be 

put  out  of  sight  in  planning  the  courses  of  different  Obser- 
vatories."— In  this  year  De  Launay's  Lunar  Theory  was 
published.  This  valuable  work  was  of  great  service  to  Airy 
in  the  preparation  of  the  Numerical  Lunar  Theory,  which  he 
subsequently  undertook. — In  the  latter  part  of  this  year  Airy 
was  elected  President  of  the  Royal  Society,  and  held  the 
office  during  1872  and  1873.  At  this  time  he  was  much 
pressed  with  work,  and  could  ill  afford  to  take  up  additional 
duties,  as  the  following  quotation  from  a  letter  to  one  of  his 
friends  shews  :  "  The  election  to  the  Presidency  of  R.  S.  is 
flattering,  and  has  brought  to  me  the  friendly  remembrances  of 
many  persons ;  but  in  its  material  and  laborious  connections, 
I  could  well  have  dispensed  with  it,  and  should  have  done  so 
but  for  the  respectful  way  in  which  it  was  pressed  on  me." 

Of  private  history :  There  was  the  usual  winter  visit  to 
Playford. — In  April  he  made  a  short  trip  to  Cornwall  with 
his  daughter  Annot.— In  June  he  was  appointed  a  Companion 
of  the  Bath,  and  was  presented  at  Court  on  his  appointment. 
— Mrs  Airy  was  staying  with  her  daughter,  Mrs  Routh,  at 
Hunstanton,  during  June,  her  state  of  health  being  somewhat 
improved.  —  From  August  1st  to  28th  he  was  chiefly  in 
Cumberland,  at  Barrow  House,  and  at  Grange,  Borrowdale, 
where  his  son  Osmund  was  staying  for  a  holiday. 


1872 

"  From  the  Report  to  the  Board  of  Visitors  it  appears 
that  '  The  Normal  Sidereal  Clock  for  giving  sidereal  time  by 
galvanic  communication  to  the  Astronomical  Observatory 
was  established  in  the  Magnetic  Basement  in  1871,  June; 
that  locality  being  adapted  for  it  on  account  of  the  uniformity 
of  temperature,  the  daily  changes  of  temperature  rarely  ex- 
ceeding i°  Fahrenheit.  Its  escapement  is  one  which  I  sug- 


294  GEORGE   BIDDELL  AIRY. 

gested  many  years  ago  in  the  Cambridge  Transactions;  a 
detached  escapement,  very  closely  analogous  to  the  ordinary 
chronometer  escapement,  the  pendulum  receiving  an  impulse 
only  at  alternate  vibrations... /the  steadiness  of  rate  is  very 
far  superior  to  any  that  we  have  previously  attained.' — The 
aspect  of  railway  enterprise  is  at  present  favourable  to  the 
Park  and  to  the  Observatory.  The  South-Eastern  Railway 
Company  has  made  an  arrangement  with  the  Metropolitan 
Board  of  Works  for  shifting  the  course  of  the  great  Southern 
Outfall  Sewer.  This  enables  the  Company  to  trace  a  new 
line  for  the  railway,  passing  on  the  north  side  of  London 
Street,  at  such  a  distance  from  the  Observatory  as  to  remove 
all  cause  of  alarm.  I  understand  that  the  Bill,  which  was 
unopposed,  has  passed  the  Committee  of  the  House  of 
Commons.  I  trust  that  the  contest,  which  has  lasted  thirty- 
seven  years,  is  now  terminated. — The  observations  of  7  Dra- 
conis  with  the  Water-Telescope,  made  in  the  autumn  of  1871, 
and  the  spring  of  1872,  are  reduced,  the  latter  only  in  their 
first  steps.... Using  the  values  of  the  level  scales  as  determined 
by  Mr  Simms  (which  I  have  no  reason  to  believe  to  be  inac- 
curate) the  spring  and  autumn  observations  of  1871  abso- 
lutely negative  the  idea  of  any  effect  being  produced  on  the 
constant  of  aberration  by  the  amount  of  refracting  medium 
traversed  by  the  light. — The  great  Aurora  of  1872  Feb.  4 
was  well  observed.  On  this  occasion  the  term  Borealis  would 
have  been  a  misnomer,  for  the  phenomenon  began  in  the 
South  and  was  most  conspicuous  in  the  South.  Three  times 
in  the  evening  it  exhibited  that  umbrella-like  appearance 
which  has  been  called  (perhaps  inaccurately)  a  corona.  I 
have  very  carefully  compared  its  momentary  phenomena 
with  the  corresponding  movements  of  the  magnetometers.  In 
some  of  the  most  critical  times,  the  comparison  fails  on  ac- 
count of  the  violent  movements  and  consequent  faint  traces 
of  the  magnetometers.  I  have  not  been  able  to  connect  the 
phases  of  aurora  and  those  of  magnetic  disturbance  very 
distinctly. — The  Report  contains  a  detailed  account  of  the 


AT   GREENWICH   OBSERVATORY — 1 866  TO    1876.        2Q5 


heavy  preparations  for  the  observation  of  the  Transit  of 
Venus  1874,  including  the  portable  buildings  for  the  instru- 
ments, the  instruments  themselves  (being  a  transit-instru- 
ment, an  altazimuth,  and  an  equatoreal,  for  each  station), 
and  first  class  and  second-class  clocks,  all  sufficient  for  the 
equipment  of  5  stations,  and  continues  thus:  I  was  made 
aware  of  the  assent  of  the  Government  to  the  wish  of  the 
Board  of  Visitors,  as  expressed  at  their  last  meeting,  that 
provision  should  be  made  for  the  application  of  photography 
to  the  observation  of  the  Transit  of  Venus.  It  is  unnecessary 
for  me  to  remark  that  our  hope  of  success  is  founded  entirely 
on  our  confidence  in  Mr  De  La  Rue.  Under  his  direction, 
Mr  Dallmeyer  has  advanced  far  in  the  preparation  of  five 
photoheliographs....The  subject  is  recognized  by  many  as- 
tronomers as  not  wholly  free  from  difficulties,  but  it  is 
generally  believed  that  these  difficulties  may  be  overcome, 
and  Mr  De  La  Rue  is  giving  careful  attention  to  the  most 
important  of  them. — I  take  this  opportunity  of  reporting  to 
the  Board  that  the  Observatory  was  honoured  by  a  visit  of 
His  Majesty  the  Emperor  of  Brazil,  who  minutely  examined 
every  part." — After  referring  to  various  subjects  which  in  his 
opinion  might  be  usefully  pursued  systematically  at  the 
Observatory,  the  Report  proceeds  thus :  " '  The  character  of 
the  Observatory  would  be  somewhat  changed  by  this  inno- 
vation, but  not,  as  I  imagine,  in  a  direction  to  which  any 
objection  can  be  made.  It  would  become,  pro  tanto,  a 
physical  observatory ;  and  possibly  in  time  its  operations 
might  be  extended  still  further  in  a  physical  direction.' — The 
consideration  of  possible  changes  in  the  future  of  the  Obser- 
vatory leads  me  to  the  recollection  of  actual  changes  in  the 
past.  In  my  Annual  Reports  to  the  Visitors  I  have  en- 
deavoured to  chronicle  these ;  but  still  there  will  be  many 
circumstances  which  at  present  are  known  only  to  myself, 
but  which  ought  not  to  be  beyond  the  reach  of  history.  I 
have  therefore  lately  employed  some  time  in  drawing  up  a 
series  of  skeleton  annals  of  the  Observatory  (which  unavoid- 


296  GEORGE   BIDDELL  AIRY. 

ably  partakes  in  some  measure  of  the  form  of  biography), 
and  have  carried  it  through  the  critical  period,  1836 — 1851. 
If  I  should  command  sufficient  leisure  to  bring  it  down  to 
1861, 1  think  that  I  might  then  ytry  well  stop."  (The  skeleton 
annals  here  referred  to  are  undoubtedly  the  manuscript  notes 
which  form  the  basis  of  the  present  biography.  Ed.) — "  On 
Feb.  23rd  in  this  year  I  first  (privately)  formed  the  notion  of 
preparing  a  numerical  Lunar  Theory  by  substituting  De- 
launay's  numbers  in  the  proper  Equations  and  seeing  what 
would  come  of  it." 

Of  private  history :  There  was  the  usual  visit  to  Playford 
— in  this  year  later  than  usual — from  Feb.  4th  to  Mar.  4th. 
The  letters  written  during  this  visit  are,  as  usual,  full  of 
freshness  and  delight  at  finding  himself  in  his  favourite 
country  village. — On  June  5th  he  went  to  Barrow  House, 
near  Keswick,  to  be  present  at  the  marriage  of  his  second 
son  Hubert  to  Miss  S.  C.  Langton,  daughter  of  Z.  Langton 
Esq.,  of  Barrow  House. — After  the  wedding  he  made  a  trip 
through  the  Trossachs  district  of  Scotland  with  his  daughter 
Annot,  and  returned  to  Greenwich  on  June  i/th. 

On  the  26th  June  1872  Airy  was  appointed  a  Knight 
Commander  of  the  Most  Honourable  Order  of  the  Bath :  he 
was  knighted  by  the  Queen  at  Osborne  on  the  3Oth  of  July. 
In  the  course  of  his  official  career  he  had  three  times  been 
offered  Knighthood,  and  had  each  time  declined  it :  but  it 
seemed  now  as  if  his  scruples  on  the  subject  were  removed, 
and  it  is  probable  that  he  felt  gratified  by  the  public  recog- 
nition of  his  services.  Of  course  the  occasion  produced 
many  letters  of  congratulation  from  his  friends :  to  one 
of  these  he  replied  as  follows  :  "  The  real  charm  of  these 
public  compliments  seems  to  be,  that  they  excite  the 
sympathies  and  elicit  the  kind  expressions  of  private  friends 
or  of  official  superiors  as  well  as  subordinates.  In  every 
way  I  have  derived  pleasure  from  these."  From  the  As- 
sistants of  the  Royal  Observatory  he  received  a  hearty  letter 
of  congratulation  containing  the  following  paragraph.  "  Our 


AT  GREENWICH   OBSERVATORY — 1 866   TO    1876.        297 

position  has  naturally  given  us  peculiar  opportunities  for 
perceiving  the  high  and  broad  purposes  which  have  charac- 
terized your  many  and  great  undertakings,  and  of  witnessing 
the  untiring  zeal  and  self-denial  with  which  they  have  been 
pursued." 


On  the  1 8th  of  March  1872  Airy  was  nominated  a  Foreign 
Associate  of  the  Institut  de  France,  to  fill  the  place  vacant 
by  the  death  of  Sir  John  Herschel.  The  following  letter  of 
acknowledgment  shews  how  much  he  was  gratified  by  this 
high  scientific  honour : 

ROYAL  OBSERVATORY,  GREENWICH, 
1872,  March  23. 

A  Messieurs 

Messieurs  ELIE  DE  BEAUMONT, 

et  J.  B.  DUMAS, 
Secretaires  perpetuels  de  I'Academie 

des  Sciences,  Institut  de  France. 

GENTLEMEN, 

I  am  honoured  with  your  letter  of  March  18,  communi- 
cating to  me  my  nomination  by  the  Academy  of  Sciences  to  the 
place  rendered  vacant  in  the  class  of  Foreign  Associates  of  the 
Academy  by  the  decease  of  Sir  John  Herschel,  and  enclosing  Copy 
of  the  Decree  of  the  President  of  the  French  Republic  approving  the 
Election. 

It  is  almost  unnecessary  for  me  to  attempt  to  express  to  you  the 
pride  and  gratification  with  which  I  receive  this  announcement.  By 
universal  consent,  the  title  of  Associe  Etranger  de  V Academic  des 
Sciences  is  recognised  as  the  highest  distinction  to  which  any  man  of 
science  can  aspire ;  and  I  can  scarcely  imagine  that,  unless  by  the 
flattering  interpretation  of  my  friends  in  the  Academy,  I  am  entitled 
to  bear  it.  But  in  any  case,  I  am  delighted  to  feel  that  the  bands  of 
friendship  are  drawn  closer  between  myself  and  the  distinguished 
body  whom,  partly  by  personal  intercourse,  partly  by  correspondence, 
and  in  every  instance  by  reputation,  I  have  known  so  long. 


298  GEORGE  BIDDELL   AIRY. 

I  beg  that  you  will  convey  to  the  Academy  my  long-felt  esteem 
for  that  body  in  its  scientific  capacity,  and  my  deep  recognition  of 
its  friendship  to  me  and  of  the  honor  which  it  has  conferred  on  me 
in  the  late  election.  ^ 

I  have'  the  honor  to  be 

Gentlemen, 
Your  very  faithful  servant, 

G.  B.  AIRY. 


On  the  2Oth  November  1872  Airy  was  nominated  a 
Grand  Cross  in  the  Imperial  Order  of  the  Rose  of  Brazil : 
the  insignia  of  the  Order  were  accompanied  by  an  autograph 
letter  from  the  Emperor  of  Brazil,  of  which  the  following  is  a 
transcript. 

MONSIEUR, 

Vous  etes  un  des  doyens  de  la  science,  et  le  President  de 
1'illustre  Societe,  qui  a  eu  la  bienveillance  d'inscrire  mon  nom  parmi 
ceux  de  ses  associe's.  La  maniere,  dont  vous  m'avez  fait  les  hon- 
neurs  de  votre  Observatoire  m'a  impose  aussi  1'agreable  devoir 
d'indiquer  votre  nom  a  1'empereur  de  Bresil  pour  un  temoignage  de 
haute  estime,  dont  je  suis  fort  heureux  de  vous  faire  part  personelle- 
ment,  en  vous  envoyant  les  decorations  que  vous  garderez,  au  moins, 
comme  un  souvenir  de  ma  visite  a  Greenwich. 

J'espere  que  vous  m'informerez,  quand  il  vous  sera  aise,  des 
travaux  de  votre  observatoire,  et  surtout  de  ce  que  Ton  aura  fait 
pour  1'observation  du  passage  de  Venus  et  la  de'termination  exacte 
de  la  passage. 

J'ai  re$u  deja  les  Proceedings  de  la  Royal  Society  lesquels  m'inte- 
ressent  vivement. 

Je  voudrais  vous  e'crire  dans  votre  langue,  mais,  comme  je  n'en 
ai  pas  1'habitude,  j'ai  craigne  de  ne  pas  vous  exprimer  tout-a-fait  les 
sentiments  de 

Votre  affectionne, 

D.  PEDRO  D'ALCANTARA. 
Rio, 

22  Octobre,  1872. 


AT  GREENWICH   OBSERVATORY — 1 866  TO    1876.        299 

Airy's  reply  was  as  follows : 

ROYAL  OBSERVATORY,  GREENWICH, 

1872,  November  26. 
SIRE, 

I  am  honoured  with  your  Imperial  Majesty's  autograph  letter 
of  October  22  informing  me  that,  on  considering  the  attention  which 
the  Royal  Society  of  London  had  been  able  to  offer  to  your  Majesty, 
as  well  as  the  explanation  of  the  various  parts  of  the  establishment  of 
this  Observatory  which  I  had  the  honor  and  the  high  gratification  to 
communicate,  You  had  been  pleased  to  place  my  name  in  the 
Imperial  Order  of  the  Rose,  and  to  present  to  me  the  Decorations  of 
Grand  Cross  of  that  Order. 

With  pride  I  receive  this  proof  of  Your  Majesty's  recollection  of 
your  visit  to  the  scientific  institutions  of  Great  Britain. 

The  Diploma  of  the  appointment  to  the  Order  of  the  Rose, 
under  the  Imperial  Sign  Manual,  together  with  the  Decorations  of 
the  Order,  have  been  transmitted  to  me  by  his  Excellency  Don 
Pereira  de  Andrada,  Your  Majesty's  Representative  at  the  British 
Court. 

Your  Majesty  has  been  pleased  to  advert  to  the  approaching 
Transit  of  Venus,  on  the  preparations  for  which  you  found  me 
engaged.  It  is  unfortunate  that  the  Transit  of  1874  will  not  be 
visible  at  Rio  de  Janeiro.  For  that  of  1882,  Rio  will  be  a  favourable 
position,  and  we  reckon  on  the  observations  to  be  made  there.  Your 
Majesty  may  be  assured  that  I  shall  loyally  bear  in  mind  your  desire 
to  be  informed  of  any  remarkable  enterprise  of  this  Observatory,  or 
of  any  principal  step  in  the  preparations  for  the  Transit  of  Venus 
and  of  its  results. 

I  have  the  honor  to  be 
Sire, 
Your  Imperial  Majesty's  very  faithful  servant, 

G.  B.  AIRY. 
To  His  Majesty 

The  Emperor  of  Brazil. 


Airy's  old  friend,  Adam  Sedgwick,  was  now  very  aged 
and  infirm,  but  his  spirit  was  still  vigorous,  and  he  was  warm- 
hearted as  ever.  The  following  letter  from  him  (probably  the 


300  GEORGE   BIDDELL  AIRY. 

last  of  their  long  correspondence)  was  written  in  this  year, 
and  appears  characteristic : 

TRINITY  COLLEGE,  CAMBRIDGE, 

May  10,  1872. 
MY  DEAR  AIRY, 

I  have  received  your  card  of  invitation  for  the  ist  of  June, 
and  with  great  joy  should  I  count  upon  that  day  if  1  thought  that  I 
should  be  able  to  accept  your  invitation  :  but  alas  I  have  no  hope 
of  the  kind,  for  that  humiliating  malady  which  now  has  fastened 
upon  me  for  a  full  year  and  a  half  has  not  let  go  its  hold,  nor  is  it 
likely  to  do  so.  A  man  who  is  journeying  in  the  88th  year  of  his 
pilgrimage  is  not  likely  to  throw  off  such  a  chronic  malady.  Indeed 
were  I  well  enough  to  come  I  am  deaf  as  a  post  and  half  blind,  and 
if  I  were  with  you  I  should  only  be  able  to  play  dummy.  Several 
years  have  passed  away  since  I  was  last  at  your  Visitation  and  I  had 
great  joy  in  seeing  Mrs  Airy  and  some  lady  friends  at  the  Obser- 
vatory, but  I  could  not  then  attend  the  dinner.  At  that  Meeting 
were  many  faces  that  I  knew,  but  strangely  altered  by  the  rude 
handling  of  old  Time,  and  there  were  many  new  faces  which  I  had 
never  seen  before  at  a  Royal  Society  Meeting ;  but  worse  than  all, 
all  the  old  faces  were  away.  In  vain  I  looked  round  for  Wollaston, 
Davy,  Davies  Gilbert,  Barrow,  Troughton,  &c.  &c.  ;  and  the  merry 
companion  Admiral  Smyth  was  also  away,  so  that  my  last  visit  had 
its  sorrowful  side.  But  why  should  I  bother  you  with  these  old 
man's  mopings. 

I  send  an  old  man's  blessing  and  an  old  man's  love  to  all  the 
members  of  your  family ;  especially  to  Mrs  Airy,  the  oldest  and 
dearest  of  my  lady  friends. 

I  remain,  my  dear  Airy, 

Your  true-hearted  old  friend, 

his 

ADAM  X  SEDGWICK. 
mark 

P.S.  Shall  I  ever  again  gaze  with  wonder  and  delight  from  the 
great  window  of  your  Observatory, 

The  body  of  the  above  letter  is  in  the  handwriting  of  an 
amanuensis,  but  the  signature  and  Postscript  are  in  Sedgwick's 
handwriting.  (Ed.) 


AT  GREENWICH   OBSERVATORY — 1 866  TO    1876.        301 


1873 


"  Chronographic  registration  having  been  established  at 
the  Paris  Observatory,  Mr  Hilgard,  principal  officer  of  the 
American  Coast  Survey,  has  made  use  of  it  for  determining 
the  longitude  of  Harvard  from  Greenwich,  through  Paris, 
Brest,  and  St  Pierre.  For  this  purpose  Mr  Hilgard's  Transit 
Instrument  was  planted  in  the  Magnetic  Court.  I  understand 
that  the  result  does  not  sensibly  differ  from  that  obtained  by 
Mr  Gould,  through  Valentia  and  Newfoundland. — It  was 
known  to  the  scientific  world  that  several  of  the  original 
thermometers,  constructed  by  Mr  Sheepshanks  (in  the  course 
of  his  preparation  of  the  National  Standard  of  Length)  by 
independent  calibration  of  the  bores,  and  independent  deter- 
mination of  the  freezing  and  boiling  points  on  arbitrary 
graduations,  were  still  preserved  at  the  Royal  Observatory. 
It  was  lately  stated  to  me  by  M.  Tresca,  the  principal  officer 
of  the  International  Metrical  Commission,  that,  in  the  late 
unhappy  war  in  Paris,  the  French  original  thermometers  were 
destroyed  ;  and  M.  Tresca  requested  that,  if  possible,  some  of 
the  original  thermometers  made  by  Mr  Sheepshanks  might 
be  appropriated  to  the  use  of  the  International  Commission. 
I  have  therefore  transferred  to  M.  Tresca  the  three  ther- 
mometers A.  6,  S.  I,  S.  2,  with  the  documentary  information 
relating  to  them,  which  was  found  in  Mr  Sheepshanks's 
papers ;  retaining  six  thermometers  of  the  same  class  in  the 
Royal  Observatory. — The  Sidereal  Standard  Clock  continues 
to  give  great  satisfaction.  I  am  considering  (with  the  aid  of 
Mr  Buckney,  of  the  firm  of  E.  Dent  and  Co.)  an  arrangement 
for  barometric  correction,  founded  on  the  principle  of  action 
on  the  pendulum  by  means  of  a  magnet  which  can  be  raised 
or  lowered  by  the  agency  of  a  large  barometer. — The  Altazi- 
muth has  received  some  important  alterations.  An  examina- 
tion of  the  results  of  observations  had  made  me  dissatisfied 


302  GEORGE   BIDDELL  AIRY. 

with  the  bearings  of  the  horizontal  pivots  in  their  Y's.  Mr 
Simms,  at  my  request,  changed  the  bearings  in  Y's  for  bearing 
in  segments  of  circles,  a  construction  which  has  worked 
admirably  well  in  the  pivots  of  the  Transit  Circle."  (And  in 
various  other  respects  the  instrument  appears  to  have  received 
a  thorough  overhauling.  Ed.) — ''With  the  consent  of  the  Royal 
Society  and  of  the  Kew  Committee,  the  Kew  fieliograph  has 
been  planted  in  the  new  dome  looking  over  the  South  Ground. 
It  is  not  yet  finally  adjusted. — Some  magnetic  observations 
in  the  Britannia  and  Conway  tubular  bridges  were  made  last 
autumn.  For  this  purpose  I  detached  an  Assistant  (Mr  Car- 
penter), who  was  aided  by  Capt.  Tupman,  R.M.A. ;  in  other 
respects  the  enterprise  was  private  and  at  private  expense. — 
The  rates  of  the  first  six  chronometers  (in  the  annual  trials) 
are  published,  in  a  form  which  appears  most  likely  to  lead  to 
examination  of  the  causes  that  influence  their  merits  or 
demerits.  This  report  is  extensively  distributed  to  British 
and  Foreign  horologists  and  instrument-makers.  All  these 
artists  appear  to  entertain  the  conviction  that  the  careful 
comparisons  made  at  this  Observatory,  and  the  orderly  form 
of  their  publication,  have  contributed  powerfully  to  the  im- 
provement of  chronometers. — Very  lately,  application  has 
been  made  to  me,  through  the  Board  of  Trade,  for  plans  and 
other  information  regarding  time-signal-balls,  to  assist  in 
guiding  the  authorities  of  the  German  Empire  in  the  estab- 
lishment of  time  signals  at  various  ports  of  that  State.  In 
other  foreign  countries  the  system  is  extending,  and  is  referred 
to  Greenwich  as  its  origin. — The  arrangements  and  prepara- 
tions for  the  observation  of  the  Transit  of  Venus  occupied 
much  attention.  With  regard  to  the  photoheliographs  it  is 
proposed  to  make  trial  of  a  plan  proposed  by  M.  Janssen,  for 
numerous  photographs  of  Venus  when  very  near  to  the  Sun's 
limb.  On  Apr.  26th  the  engaging  of  photographic  teachers 
was  sanctioned.  Observers  were  selected  and  engaged.  A 
working  model  of  the  Transit  was  prepared,  and  the  use  of 
De  La  Rue's  Scale  was  practised.  There  was  some  hostile 


AT   GREENWICH   OBSERVATORY — 1 866   TO    1 876.        303 

criticism  of  the  stations  selected  for  the  observation  of  the 
Transit,  which  necessitated  a  formal  reply. — Reference  is 
made  to  the  increase  of  facilities  for  making  magnetical  and 
meteorological  observations.  The  inevitable  result  of  it. is, 
that  observations  are  produced  in  numbers  so  great  that 
complete  reduction  becomes  almost  impossible.  The  labour 
of  reduction  is  very  great,  and  it  is  concluded  that,  of  the 
enormous  number  of  meteorological  observations  now  made 
at  numerous  observatories,  very  few  can  ever  possess  the 
smallest  utility. — Referring  to  my  Numerical  Lunar  Theory  : 
on  June  3Oth,  1873,  a  theory  was  formed,  nearly  but  not  per- 
fectly complete.  Numerical  development  of  powers  of  a  -r  r 
and  r  -r-  a.  Factors  of  corrections  to  Delaunay  first  attempted, 
but  entirely  in  numerical  form." — In  March  of  this  year  Airy 
was  consulted  by  Mr  W.  H.  Barlow,  C.E.,  and  Mr  Thomas 
Bouch  (the  Engineer  of  the  Tay  Bridge,  which  was  blown 
down  in  1879,  and  of  a  proposed  scheme  for  a  Forth  Bridge 
in  1873)  on  the  subject  of  the  wind  pressure,  &c.,  that  should 
be  allowed  for  in  the  construction  of  the  bridge.  Airy's 
report  on  this  question  is  dated  1873,  Apr.  Qth:  it  was  subse- 
quently much  referred  to  at  the  Official  Enquiry  into  the 
causes  of  the  failure  of  the  Tay  Bridge. — At  the  end  of  this 
year  Airy  resigned  the  Presidency  of  the  Royal  Society.  In 
his  Address  to  the  Society  on  Dec.  ist  he  stated  his  reasons 
in  full,  as  follows  :  "  the  seventy  of  official  duties,  which  seem 
to  increase,  while  vigour  to  discharge  them  does  not  increase ; 
and  the  distance  of  my  residence.... Another  cause  is  a  diffi- 
culty of  hearing,  which  unfits  me  for  effective  action  as  Chair- 
man of  Council. " 

Of  private  history :  There  was  the  usual  visit  to  Play- 
ford  in  January :  also  a  short  visit  in  May :  and  a  third  visit 
at  Christmas. — There  was  a  short  run  in  June,  of  about  a 
week,  to  Coniston,  with  one  of  his  daughters. — And  there  was 
a  trip  to  Weymouth,  &c.,  for  about  10  days,  with  one  of  his 
daughters,  in  the  beginning  of  August. — On  his  return  from 
the  last-mentioned  trip,  Airy  found  a  letter  from  the  Secretary 


304  GEORGE  BIDDELL  AIRY. 

of  the  Swedish  Legation,  enclosing  the  Warrant  under  the 
Royal  Sign  Manual  of  His  Majesty  (Oscar),  the  King  of 
Sweden  and  Norway,  by  which  he  was  nominated  as  a  First 
Class  Commander  of  the  Order  of  the  North  Star,  and  accom- 
panying the  Decorations  of  that  Order. 


1874 

"In  this  year  Mr  Glaisher  resigned  his  appointment:  I 
placed  his  Department  (Magnetical  and  Meteorological) 
under  Mr  Ellis. — A  balance  of  peculiar  construction  has  been 
made  by  Mr  Oertling,  from  my  instructions,  and  fixed  near 
the  public  barometer  at  the  Entrance  Gate.  This  instrument 
enables  the  public  to  test  any  ordinary  pound  weight,  shewing 
on  a  scale  the  number  of  grains  by  which  it  is  too  heavy  or 
too  light. — Fresh  counterpoises  have  been  attached  to  the 
Great  Equatoreal  to  balance  the  additional  weight  of  the  new 
Spectroscope,  which  was  finally  received  from  Mr  Browning's 
/  hands  on  May  2nd  of  the  present  year.  The  Spectroscope  is 
specifically  adapted  to  sweeping  round  the  Sun's  limb,  with  a 
view  to  mapping  out  the  prominences,  and  is  also  available 
for  work  on  Stars  and  Nebulae,  the  dispersive  power  being 
very  readily  varied.  An  induction-coil,  capable  of  giving  a 
six-inch  spark,  has  been  made  for  this  instrument  by  Mr 
Browning. — Some  new  classes  of  reductions  of  the  meteoro- 
logical observations  from  1848  to  1868  have  been  undertaken 
and  completed  in  the  past  year.  The  general  state  of  this 
work  is  as  follows :  The  diurnal  changes  of  the  dry-bulb 
thermometer,  as  depending  on  the  month,  on  the  temperature 
waves,  on  the  barometric  waves,  on  the  overcast  and  cloudless 
states  of  the  sky,  and  on  the  direction  of  the  wind,  have  been 
computed  and  examined  for  the  whole  period ;  and  the  exhi- 
bition of  the  results  is  ready  for  press.  The  similar  reductions 
for  the  wet-bulb  thermometer  are  rapidly  approaching  com- 
pletion.— Regarding  the  preparations  for  the  Transit  of  Venus 


AT  GREENWICH   OBSERVATORY — 1 866   TO    1876.        305 

Expeditions.  Originally  five  stations  were  selected  and  fully 
equipped  with  equatoreals,  transits,  altazimuths,  photohelio- 
graphs,  and  clocks  ;  but  I  have  since  thought  it  desirable  to 
supplement  these  by  two  branch  stations  in  the  Sandwich 
Islands  and  one  in  Kerguelen's  Island  ;  and  the  additional 
instruments  thus  required  have  been  borrowed  from  various 
sources,  so  that  there  is  now  an  abundant  supply  of  instru- 
mental means.... There  will  thus  be  available  for  observation 
of  the  Transit  of  Venus  23  telescopes,  nine  of  which  will  be 
provided  with  double-image-micrometers ;  and  five  photo- 
heliographs  ;  and  for  determination  of  local  time,  and  latitude 
and  longitude,  there  will  be  nine  transits  and  six  altazimuths. 
...All  the  observers  have  undergone  a  course  of  training  in 
photography ;  first,  under  a  professional  photographer,  Mr 
Reynolds,  and  subsequently  under  Capt  Abney,  R.E.,  whose 
new  dry-plate  process  is  to  be  adopted  at  all  the  British 
Stations.... A  Janssen  slide,  capable  of  taking  50  photographs 
of  Venus  and  the  neighbouring  part  of  the  Sun's  limb  at 
intervals  of  one  second,  has  been  made  by  Mr  Dallmeyer  for 
each  of  the  five  photoheliographs." — Attached  to  the  Report 
to  the  Visitors  is  a  copy  of  the  Instructions  to  Observers 
engaged  in  the  Transit  of  Venus  Expeditions,  prepared  with 
great  care  and  in  remarkable  detail. — "  In  the  past  spring  I 
published  in  the  Monthly  Notices  of  the  Royal  Astronomical 
Society  a  statement  of  the  fundamental  points  in  a  new 
treatment  of  the  Lunar  Theory,  by  which,  availing  myself  of 
all  that  has  been  done  in  the  best  algebraical  investigations 
of  that  theory,  I  trust  to  be  able  by  numerical  operations 
only  to  give  greater  accuracy  to  final  results.  Considerable 
progress  has  been  made  in  the  extensive  numerical  develop- 
ments, the  work  being  done,  at  my  private  expense,  entirely 
by  a  junior  computer;  and  I  hope,  at  any  rate,  to  put  it  in 
such  a  state  that  there  will  be  no  liability  to  its  entire  loss. 
When  this  was  reported  to  the  Board  of  Visitors,  it  was 
resolved  on  the  motion  of  Prof.  Stokes,  that  this  work,  as  a 
public  expense,  ought  to  be  borne  by  the  Government ;  and 

A.  B.  2O 


306  GEORGE   BIDDELL  AIRY. 

this  was  forwarded  to  the  Admiralty.  On  June  24th  I  wrote 
to  the  Secretary  of  the  Admiralty,  asking  for  £100  for  the 
present  year,  which  after  the  usual  enquiries  and  explanations 
was  sanctioned  on  Aug.  29th."  f 

Of  private  history :  There  were  short  visits  to  Playford 
in  January,  June,  and  October,  but  only  for  a  few  days  in 
each  case. — In  March  there  was  a  run  of  two  or  three  days  to 
Newnham  (on  the  Severn)  to  see  the  Bore  on  the  Severn, 
and  to  Malvern. — In  July  he  went  to  Newcastle  to  observe 
with  Mr  Newall's  great  telescope,  but  the  weather  was  un- 
favourable :  he  then  went  on  to  Barrow  House  near  Keswick, 
and  spent  a  few  days  there,  with  excursions  among  the 
mountains. — On  Aug.  I3th  he  went  with  his  daughter  Christ- 
abel  to  the  Isle  of  Arran,  and  then  by  Glasgow  to  the 
Trosachs,  where  he  made  several  excursions  to  verify  the 
localities  mentioned  in  the  "  Lady  of  the  Lake." — While  in 
Scotland  he  heard  of  the  death  of  his  brother,  the  Rev. 
William  Airy,  and  travelled  to  Keysoe  in  Bedfordshire  to 
attend  the  funeral ;  and  returned  to  Greenwich  on  Aug.  24th. 


1875 

"  In  October  of  this  year  I  wrote  to  the  Admiralty  that 
I  had  grounds  for  asking  for  an  increase  of  my  salary:  be- 
cause the  pension  which  had  been  settled  on  my  wife,  and 
which  I  had  practically  recognized  as  part  of  my  salary,  had 
been  terminated  by  her  death ;  so  that  my  salary  now  stood 
lower  by  ^200  than  that  of  the  Director  of  Studies  of  the 
Royal  Naval  College.  The  Admiralty  reply  favourably,  and 
on  Nov.  2/th  the  Treasury  raise  my  salary  to  .£1,200. — For 
the  service  of  the  Clock  Movement  of  the  Great  Equatoreal, 
a  water-cistern  has  been  established  in  the  highest  part  of 
the  Ball-Turret,  the  necessity  for  which  arose  from  the  fol- 
lowing circumstance :  The  Water  Clock  was  supplied  by  a 
small  pipe,  about  80  feet  in  length,  connected  with  the 


AT  GREENWICH   OBSERVATORY — 1 866  TO    1876.        307 

3-inch  Observatory  main  (which  passes  through  the  Park), 
at  a  distance  of  about  250  feet  from  any  other  branch  pipe. 
In  spite  of  this  distance  I  have  seen  that,  on  stopping  the 
water-tap  in  the  Battery-Basement  under  the  North-East 
Turret,  the  pressure  in  the  gauge  of  the  Water  Clock  has 
been  instantly  increased  by  more  than  40  Ibs.  per  square 
inch.  The  consequent  derangement  of  the  Water  Clock  in 
its  now  incessant  daily  use  became  intolerable.  Since  the 
independent  supply  was  provided,  its  performance  has  been 
most  satisfactory. — With  the  Spectroscope  the  solar  pro- 
minences have  been  mapped  on  28  days  only;  but  the 
weather  of  the  past  winter  was  exceptionally  unfavour- 
able for  this  class  of  observation.  After  mapping  the  pro- 
minences, as  seen  on  the  C  line,  the  other  lines,  especially 
F  and  b,  have  been  regularly  examined,  whenever  prac- 
ticable. Great  care  has  been  taken  in  determining  the 
position,  angle,  and  heights  of  the  prominences  in  all  cases. 
The  spectrum  of  Coggia's  Comet  was  examined  at  every 
available  opportunity  last  July,  and  compared  directly  with 
that  of  carbon  dioxide,  the  bands  of  the  two  spectra  being 
sensibly  coincident.  Fifty-four  measures  of  the  displacement 
of  lines  in  the  spectra  of  10  stars,  as  compared  with  the 
corresponding  lines  in  the  spectra  of  terrestrial  elements 
(chiefly  hydrogen),  have  been  made,  but  some  of  these  ap- 
pear to  be  affected  by  a  constant  error  depending  on  faulty 
adjustment  of  the  Spectroscope. — Photographs  of  the  Sun 
have  been  taken  with  the  Kew  Photoheliograph  on  186 
days ;  and  of  these  377  have  been  selected  for  preservation. 
The  Moon,  Jupiter,  Saturn,  and  several  stars  (including  the 
Pleiades  and  some  double  stars)  have  been  photographed 
with  the  Great  Equatoreal,  with  fairly  satisfactory  results, 
though  further  practice  is  required  in  this  class  of  work. — 
I  would  mention  a  supplemental  mechanism  which  I  have 
myself  introduced  into  some  chronometers.  I  have  long 
remarked  that,  in  ordinary  good  chronometers,  the  freedom 
from  irregularities  depending  on  mechanical  causes  is  most 

20 — 2 


308  GEORGE  BIDDELL  AIRY. 

remarkable ;  but  that,  after  all  the  efforts  of  the  most  ju- 
dicious makers,  there  is  in  nearly  every  case  a  perceptible 
defect  of  thermal  compensation.  There  is  great  difficulty 
in  correcting  the  residual  faulfcf  not  only  because  an  incon- 
ceivably small  movement  of  the  weights  on  the  balance-curve 
is  required,  but  also  because  it  endangers  the  equilibrium 
of  the  balance.  The  mechanism  adopted  to  remedy  the 
defect  is  described  in  a  Paper  in  the  Horological  Journal  of 
July  1875  by  Mr  W.  Ellis,  and  has  received  the  approval  of 
some  able  chronometer-makers. — With  respect  to  the  Transit 
of  Venus  Expeditions  :  The  parties  from  Egypt  and  Rod- 
riguez are  returned.  I  am  in  continual  expectation  of  the 
arrival  of  the  other  parties.  I  believe  the  eye-observations 
and  the  ordinary  photographs  to  be  quite  successful ;  I 
doubt  the  advantage  of  the  Janssen ;  one  of  the  double- 
image-micrometers  seems  to  have  failed ;  and  the  Zenith- 
telescope  gives  some  trouble.  At  three  stations  at  Rodri- 
guez, and  three  at  Kerguelen,  the  observations  appear  to 
have  been  most  successful.  At  the  Sandwich  Islands,  two 
of  the  stations  appear  to  have  been  perfectly  successful 
(except  that  I  fear  that  the  Janssen  has  failed),  and  a  rich 
series  of  lunar  observations  for  longitude  is  obtained.  At 
New  Zealand,  I  grieve  to  say,  the  observations  were  totally 
lost,  entirely  in  consequence  of  bad  weather.  There  has  been 
little  annoyance  from  the  dreaded  '  black  drop.'  Greater 
inconvenience  and  doubt  have  been  caused  by  the  unex- 
pected luminous  ring  round  Venus. — With  regard  to  the 
progress  of  my  proposed  New  Lunar  Theory:  Three  com- 
puters are  now  steadily  employed  on  the  work.  It  will  be 
remembered  that  the  detail  and  mass  of  this  work  are 
purely  numerical ;  every  numerical  coefficient  being  accom- 
panied with  a  symbolical  correction  whose  value  will  some- 
times depend  on  the  time,  but  in  every  case  is  ultimately 
to  be  obtained  in  a  numerical  form.  Of  these  coefficients, 
extracted  (for  convenience)  from  Delaunay's  results,  there 
are  100  for  parallax,  182  for  longitude,  142  for  latitude; 


AT   GREENWICH   OBSERVATORY — 1 866  TO    1876.       309 

the  arguments  being  preserved  in  the  usual  form." — After 
reviewing  the  changes  that  had  taken  place  at  the  Ob- 
servatory during  the  past  forty  years,  the  Report  to  the 
Board  of  Visitors  concludes  thus :  "  I  much  desire  to  see  the 
system  of  time-signals  extended,  by  clocks  or  daily  signals, 
to  various  parts  of  our  great  cities  and  our  dockyards,  and 
above  all  by  hourly  signals  on  the  Start  Point,  which  I 
believe  would  be  the  greatest  of  all  benefits  to  nautical 
chronometry.  Should  any  extension  of  our  scientific  work 
ever  be  contemplated,  I  would  remark  that  the  Observatory 
is  not  the  place  for  new  physical  investigations.  It  is  well 
adapted  for  following  out  any  which,  originating  with  pri- 
vate investigators,  have  been  reduced  to  laws  susceptible  of 
verification  by  daily  observation.  The  National  Observa- 
tory will,  I  trust,  always  remain  on  the  site  where  it  was 
first  planted,  and  which  early  acquired  the  name" of  'Flam- 
steed  Hill.'  There  are  some  inconveniences  in  the  position, 
arising  principally  from  the  limited  extent  of  the  hill,  but 
they  are,  in  my  opinion,  very  far  overbalanced  by  its  ad- 
vantages."— In  a  letter  on  the  subject  of  the  Smith's  Prizes 
Examination  at  Cambridge,  which  was  always  a  matter  of 
the  greatest  interest  to  him,  Airy  renewed  his  objections  to 
the  preponderance  in  the  Papers  of  a  class  of  Pure  Mathe- 
matics, which  he  considered  was  never  likely  under  any 
circumstances  to  give  the  slightest  assistance  to  Physics. 
And,  as  before,  these  remarks  called  forth  a  rejoinder  from 
Prof.  Cayley,  who  was  responsible  for  many  of  the  ques- 
tions of  the  class  referred  to. — In  this  year  Airy  completed 
his  "  Notes  on  the  Earlier  Hebrew  Scriptures,"  which  were 
shortly  afterwards  published  as  a  book  by  Messrs  Longmans, 
Green,  &  Co.  In  his  letter  to  the  publishers  introducing  the 
subject,  he  says,  "  For  many  years  past  I  have  at  times  put 
together  a  few  sentences  explanatory  as  I  conceive  of  the 
geographical  and  historical  circumstances  connected  with  the 
principal  events  recorded  in  the  Hebrew  Scriptures.  The 
view  which  I  take  is  free,  but  I  trust  not  irreverent.  They 


310  GEORGE   BIDDELL  AIRY. 

terminate  with  a  brief  review  of  Colenso's  great  work. 
The  collection  now  amounts  to  a  small  book."  From  the 
references  already  given  in  previous  years  to  his  Papers 
and  correspondence  on  the/"  geography  of  Exodus,  his 
correspondence  with  Colenso,  &c.  &c.,  it  will  be  seen 
that  he  took  a  great  interest  in  the  early  history  of  the 
Israelites.— On  August  loth,  1875,  Airy  celebrated  the  Bi- 
centenary of  the  Royal  Observatory  by  a  dinner  in  the 
Octagon  Room,  which  was  attended  by  the  Presidents  of 
the  Royal  Society  and  the  R.  Astr.  Society,  and  by  a  large 
number  of  Scientific  gentlemen  interested  in  Astronomy. — 
In  February  he  was  revising  his  Treatise  on  "  Probabilities." 

Of  private  history:  up  to  Jan.  i6th  Airy  was  at  Playford 
as  usual. — For  about  a  week  in  April  he  was  in  the  Isle 
of  Man  with  .his  daughter  Christabel. — In  June  there  was 
a  short  trip  to  Salisbury,  Blandford,  and  Wimborne. — On 
August  1 2th  he  started  with  his  daughter  Annot  for  a  holi- 
day in  Cumberland,  but  on  the  next  day  he  was  recalled 
by  a  telegram  with  the  intelligence  that  a  change  for  the 
worse  had  come  over  his  wife's  health.  Lady  Airy  died 
on  August  1 3th,  1875.  For  the  last  five  years  of  her  life 
she  had  been  very  helpless  from  the  effects  of  a  paralytic 
stroke — a  very  sad  ending  to  a  bright  and  happy  life — and 
had  been  continually  nursed  throughout  this  time  by  her 
two  unmarried  daughters  with  the  greatest  self-denial  and 
devotion.  Her  husband  had  been  unremitting  in  his  care 
and  attention.  Nothing  was  wanting  that  the  most  thought- 
ful kindness  could  supply.  And  in  all  his  trips  and  ex- 
cursions his  constant  and  kind  letters  shewed  how  anxious 
he  was  that  she  should  participate  in  all  his  interests  and 
amusements.  From  the  nature  of  the  case  it  could  hardly 
be  said  that  her  death  was  unexpected,  and  he  received  the 
shock  with  the  manly  steadiness  which  belonged  to  him. 
Lady  Airy  was  buried  in  Playford  churchyard. — From  Sept. 
22nd  to  Oct.  4  he  made  a  short  expedition  to  Wales  (Capel 
Curig,  &c.). — On  Dec.  i$th  he  attended  the  Commemoration 


AT   GREENWICH   OBSERVATORY— 1 866  TO    1876.        311 

at  Trinity  College,  Cambridge. — On  Dec.  22nd  he  went  as 
usual  to  Playford. 

In  this  year  Airy  received  the  high  honour  of  the  Free- 
dom of  the  City  of  London,  in  the  following  communica- 
tion : 

STONE,  Mayor. — A  Common  Council  holden  in  the  Chamber  of 
the  Guildhall  of  the  City  of  London,  on  Thursday  the  2gih  day  of 
April  1875. 

Resolved  Unanimously 

That  the  Freedom  of  this  City  in  a  Gold  Box 
of  the  value  of  One  hundred  guineas  be  presented  to  Sir  George 
Biddell  Airy,  K.C.B.,  D.C.L.,  LL.D.  &c.,  Astronomer  Royal,  as  a 
recognition  of  his  indefatigable  labours  in  Astronomy,  and  of  his 
eminent  services  in  the  advancement  of  practical  science,  whereby 
he  has  so  materially  benefited  the  cause  of  Commerce  and  Civiliza- 
tion. 

MONCKTON. 


This  Resolution  was  forwarded  with  a  letter  from  Ben- 
jamin Scott,  the  Chamberlain.     Airy's  reply  was  as  follows  : 

ROYAL  OBSERVATORY,  GREENWICH,  S.E. 
1875,  May  i. 


DEAR  SIR, 

I  have  the  honour  to  acknowledge  your  letter  of  April  30, 
accompanied  with  Copy  of  the  Resolution  of  the  Common  Council 
of  the  City  of  London  passed  at  their  Meeting  of  April  29,  under 
signature  of  the  Town  Clerk,  That  the  Freedom  of  the  City  of 
London  in  a  valuable  Box  be  presented  to  me,  in  recognition  of 
works  stated  in  the  Resolution.  And  I  am  requested  by  you  to 
inform  you  whether  it  is  my  intention  to  accept  the  compliment 
proposed  by  the  Corporation. 

In  reply,  I  beg  you  to  convey  to  the  Right  Honorable  the  Lord 
Mayor  and  the  Corporation  that  I  accept  with  the  greatest  pride 
and  pleasure  the  honour  which  they  propose  to  offer  to  me.  The 
Freedom  of  our  Great  City,  conferred  by  the  spontaneous  act  of 


312  GEORGE   BIDDELL  AIRY. 

its  Municipal  Governors,  is  in  my  estimation  the  highest  honour 
which  it  is  possible  to  receive ;  and  its  presentation  at  this  time  is 
peculiarly  grateful  to  me. 

I  have  the  honour  ftb  be, 
Sir, 
Your  very  obedienjj  servant, 

G.    B.   AIRY. 
Benjamin  Scott,  Esq., 

drv.         &c.         &c. 
Chamberlain  of  the  Corporation  of  the 
City  of  London. 

As  it  was  technically  necessary  that  a  Freeman  of  the 
City  of  London  should  belong  to  one  or  other  of  the  City 
Companies,  the  Worshipful  Company  of  Spectacle  Makers 
through  their  clerk  (with  very  great  appropriateness)  en- 
quired whether  it  would  be  agreeable  that  that  Company 
should  have  the  privilege  of  conferring  their  Honorary  Free- 
dom on  him,  and  added:  "In  soliciting  your  acquiescence 
to  the  proposal  I  am  directed  to  call  attention  to  the  fact 
that  this  Guild  is  permitted  to  claim  all  manufacturers  of 
Mathematical  and  Astronomical  Instruments  within  the  City 
of  London,  which  is  now  pleaded  as  an  apology  for  the  wish 
that  one  so  distinguished  as  yourself  in  the  use  of  such  In- 
struments should  be  enrolled  as  a  Member  of  this  Craft." 
In  his  reply,  accepting  the  Freedom  of  the  Company,  Airy 
wrote  thus  :  "  I  shall  much  value  the  association  with  a  body 
whose  ostensible  title  bears  so  close  a  relation  to  the  official 
engagements  which  have  long  occupied  me.  I  have  had  ex- 
tensive experience  both  in  arranging  and  in  using  optical 
and  mathematical  instruments,  and  feel  that  my  own  pur- 
suits are  closely  connected  with  the  original  employments 
of  the  Company."  The  Freedom  of  the  Company  was  duly 
presented,  and  the  occasion  was  celebrated  by  a  banquet  at 
the  Albion  Tavern  on  Tuesday,  July  6th. 

The  Freedom  of  the  City  of  London  was  conferred  at 


AT  GREENWICH   OBSERVATORY— 1 866  TO    1 876.       313 

a  Court  of  Common  Council  held  at  the  Guildhall  on 
Thursday  the  4th  of  November.  In  presenting  the  gold 
box  containing  the  Freedom,  the  Chamberlain,  in  an  elo- 
quent speech,  first  referred  to  the  fact  that  this  was  the 
first  occasion  on  which  the  Freedom  had  been  conferred 
on  a  person  whose  name  was  associated  with  the  sciences 
other  than  those  of  war  and  statecraft.  He  then  referred 
to  the  solid  character  of  his  work,  in  that,  while  others  had 
turned  their  attention  to  the  more  attractive  fields  of  ex- 
ploration, the  discovery  of  new  worlds  or  of  novel  celestial 
phenomena,  he  had  incessantly  devoted  himself  to  the  less 
interesting,  less  obtrusive,  but  more  valuable  walks  of  prac- 
tical astronomy.  And  he  instanced  as  the  special  grounds 
of  the  honour  conferred,  the  compilation  of  nautical  tables 
of  extraordinary  accuracy,  the  improvement  of  chronometers, 
the  correction  of  the  compasses  of  iron  ships,  the  restoration 
of  the  standards  of  length  and  weight,  and  the  Transit  of 
Venus  Expeditions.  In  his  reply  Airy  stated  that  he  re- 
garded the  honour  just  conferred  upon  him  as  the  greatest 
and  proudest  ever  received  by  him.  He  referred  to  the  fact 
that  the  same  honour  had  been  previously  conferred  on  the 
valued  friend  of  his  youth,  Thomas  Clarkson,  and  said  that 
the  circumstance  of  his  succeeding  such  a  man  was  to  him- 
self a  great  honour  and  pleasure.  He  alluded  to  his  having 
received  a  small  exhibition  from  one  of  the  London  Com- 
panies, when  he  was  a  poor  undergraduate  at  Cambridge, 
and  acknowledged  the  great  assistance  that  it  had  been  to 
him.  With  regard  to  his  occupation,  he  said  that  he  had 
followed  it  in  a  great  measure  because  of  its  practical  use, 
and  thought  it  fortunate  that  from  the  first  he  was  con- 
nected with  an  institution  in  which  utility  was  combined 
with  science.  The  occasion  of  this  presentation  was  cele- 
brated by  a  Banquet  at  the  Mansion  House  on  Saturday 
July  3rd,  1875,  to  Sir  George  Airy  (Astronomer  Royal)  and 
the  Representatives  of  Learned  Societies. 

There   is   no   doubt   that   Airy  was   extremely  gratified 


314  GEORGE   BIDDELL  AIRY. 

by  the  honour  that  he  had  received.  It  was  to  him  the 
crowning  honour  of  his  life,  and  coming  last  of  all  it  threw 
all  his  other  honours  into  the  shade.  To  his  independent 
and  liberal  spirit  there'  was  something  peculiarly  touching 
in  the  unsolicited  approbation  and  act  of  so  powerful  and 
disinterested  a  body  as  the  Corporation  of  the  City  of  London. 


CHAPTER    IX. 

AT  GREENWICH  OBSERVATORY  FROM  JANUARY  IST,  1876, 
TO  HIS  RESIGNATION  OF  OFFICE  ON  AUGUST  ISTH, 
1881. 

1876 

"AT  the  door  from  the  Front  Court  to  the  staircase  of  the 
Octagon  Room  (the  original  entrance  to  the  Observatory  as 
erected  by  Sir  Christopher  Wren),  a  small  porch-shelter  has 
been  often  desired.  I  proposed  to  fix  there  a  fan-roof  of 
quadrantal  form,  covering  the  upper  flat  stone  of  the  external 
steps. — On  a  critical  examination  of  the  micrometer-screws 
of  the  Transit  Circle  it  was  found  that  the  corrections,  which 
range  from  —  1*38"  to +  076",  indicate  considerable  wear  in 
the  screws ;  and  it  was  found  that  as  much  as  one-hundreth 
part  of  an  inch  had  been  worn  away  from  some  of  the 
threads.  The  old  screws  were  consequently  discarded,  and 
new  ones  were  made  by  Mr  Simms. — The  adjustment  of  the 
Spectroscope  has  occupied  a  great  deal  of  attention.  There 
was  astigmatism  of  the  prisms ;  and  false  light  reflected  from 
the  base  of  the  prisms,  causing  loss  both  of  light  and  of 
definition.  The  latter  defect  was  corrected  by  altering  the 
angles,  and  then  astigmatism  was  corrected  by  a  cylindrical 
lens  near  the  slit.  The  definition  in  both  planes  was  then 
found  to  be  perfect. — The  number  of  small  planets  has  now 
become  so  great,  and  the  interest  of  establishing  the  elements 
of  all  their  orbits  so  small, — while  at  the  same  time  the  light 
of  all  those  lately  discovered  is  very  faint,  and  the  difficulty 


3l6  GEORGE   BIDDELL  AIRY. 

and  doubt  of  observation  greatly  increased, — that  I  have 
begun  to  think  seriously  of  limiting  future  observations  to  a 
small  number  of  these  objects. — All  observations  with  the 
Spectroscope  have  been  completely  reduced  ;  the  measures  of 
lines  in  the  spectra  of  elements  being  converted  into  corre- 
sponding wave-lengths,  and  the  observations,  of  displacement 
of  lines  in  the  spectra  of  stars  being  reduced  so  as  to  exhibit 
the  concluded  motion  in  miles  per  second,  after  applying  a 
correction  for  the  earth's  motion.  Sixteen  measures  of  the 
F  line  in  the  spectrum  of  the  Moon  as  compared  with 
hydrogen  give  a  displacement  corresponding  to  a  motion  of 
less  than  two  miles  a  second,  which  seems  to  shew  that  the 
method  of  comparison  now  adopted  is  free  from  systematic 
error  ;  and  this  is  supported  by  the  manner  in  which  motions 
of  approach  and  recession  are  distributed  among  the  stars 
examined  on  each  night  of  observation.  The  results  recently 
obtained  appear  to  be  on  the  whole  as  consistent  as  can  be 
expected  in  such  delicate  observations,  and  they  support  in  a 
remarkable  manner  the  conclusions  of  Dr  Huggins,  with 
regard  to  the  motions  of  those  stars  which  he  examined. — 
Photographs  of  the  sun  have  been  taken  with  the  photo- 
heliograph  on  182  days.  On  one  of  the  photographs,  which 
was  accidentally  exposed  while  the  drop  slit  was  being  drawn 
up,  there  appears  to  be  a  faint  image  of  a  cloud-like  promi- 
nence close  to  the  sun's  limb,  though  the  exposure  probably 
only  amounted  to  a  fraction  of  a  second.  A  prominence  of 
unusual  brilliancy  was  seen  with  the  Spectroscope  about  the 
same  time  and  in  the  same  position  with  reference  to  the 
Sun's  limb.  All  groups  of  Sun-spots  and  faculae  have  been 
numbered,  and  the  dates  of  their  first  and  last  appearances 
entered  up  to  the  present  time.  Areas  of  spots  have  been 
measured,  and  the  measures  have  been  reduced  to  millionths 
of  the  Sun's  visible  hemisphere. — The  examination  of  the 
readings  of  the  deep-sunk  thermometers  from  1846  to  1873 
has  exhibited  some  laws  which  had  been  sufficiently  estab- 
lished before  this  time,  and  some  which  were  less  known. 


AT  GREENWICH  OBSERVATORY— 1876  TO    l88l.       317 

Among  the  former  were  the  successive  retardations  of  seasons 
in  successive  descents,  amounting  to  about  four  months  at  the 
depth  of  25  feet ;  and  the  successive  diminutions  of  the  annual 
range  of  temperature.  Among  the  latter  is  the  character  of 
the  changes  from  year  to  year,  which  the  great  length  of  this 
series  of  observations  brings  well  to  light.  It  is  found  that 
from  year  to  year  the  mean  temperature  of  the  surface  for 
the  year,  varying  by  three  or  four  degrees  of  Fahrenheit, 
follows  in  its  changes  the  mean  temperature  of  the  atmosphere 
for  the  year,  and  that  the  changes  of  annual  temperature  are 
propagated  downwards,  retarded  in  phase  and  diminishing  in 
amount  of  change,  in  the  same  manner  (though  probably  not 
following  the  same  law)  as  the  season  changes.  The  inference 
from  this  is,  that  changes  of  temperature  come  entirely  from 
the  exterior  and  in  no  discoverable  degree  from  the  interior ; 
an  inference  which  may  be  important  in  regard  both  to  solar 
action  and  to  geology. — Referring  to  the  Transit  of  Venus 
observations :  In  the  astronomical  part  of  the  reductions, 
there  has  been  great  labour  and  difficulty  in  the  determina- 
tion of  local  sidereal  times  ;  some  books  of  observations 
required  extensive  transcription  ;  some  instrumental  errors 
are  still  uncertain  ;  the  latter  determinations  have  perplexed 
us  so  much  that  we  are  inclined  to  believe  that,  in  spite  of  the 
great  facilities  of  reduction  given  by  the  transit  instrument,  it 
would  be  better  to  rely  on  the  altazimuth  for  time-determina- 
tions   In  the  photographic  part,  I  have  confined  my 

attention  entirely  to  measures  of  the  distance  between  the 
centres  of  the  Sun  and  Planet,  a  troublesome  and  complex 
operation. — Referring  to  the  progress  of  the  Numerical  Lunar 
Theory:  With  a  repetition  of  grant  from  the  Treasury,  I  have 
usually  maintained  four  junior  computers  on  this  work.  The 
progress,  though  considerable,  has  not  been  so  great  as  I  had 
hoped,  by  reason  of  the  excessive  personal  pressure  upon  me 
during  the  whole  year. — I  wrote  a  letter  of  congratulation  to 
Le  Verrier  on  the  completion  of  his  great  work  of  Planetary 
Tables. — On  May  I3th  the  Queen  was  at  South  Kensington, 


318  GEORGE   BIDDELL   AIRY. 

and  I  attended  to  explain  the  astronomical  instruments,  and 
shewed  Her  Majesty  one  of  the  Transit  of  Venus  photo- 
graphs." 

Of  private  history :  He  returned  from  his  Playford  visit 
on  the  1 8th  of  January. — In  April  there  was  a  two-day  trip 
to  Colchester. — From  June  I3th  to  July  1 2th  he  was  travelling 
in  the  North  of  Scotland  and  the  Orkneys  with  his  daughters, 
staying  for  a  short  time  with  Mr  Webster,  M.P.,  at  Aberdeen, 
and  with  Mr  Newall  at  Newcastle. — In  September  there  was 
a  week's  run  to  Birkenhead  and  Keswick. — In  November  a 
week's  run  to  Playford. — From  the  I3th  to  i$th  of  December 
he  was  at  Cambridge,  and  on  the  28th  he  went  to  Playford 
for  the  usual  winter  stay  there. 

1877 

"  In  April  of  this  year  I  was  much  engaged  on  the  subject 
of  Mr  Gill's  expedition  to  Ascension  to  observe  for  the  deter- 
mination of  the  parallax  of  Mars  at  the  approaching  opposition 
of  that  planet. — A  large  Direct-vision  Spectroscope  has  been 
quite  recently  made  by  Mr  Hilger  under  Mr  Christie's 
direction  on  a  new  plan,  in  which  either  great  dispersion  or 
great  purity  of  spectrum  is  obtained  by  the  use  of  '  Half- 
prisms/  according  as  the  incident  pencil  falls  first  on  the 
perpendicular  or  on  the  oblique  face.  In  this  Spectroscope 
either  one  or  two  half  prisms  can  be  used  at  pleasure, 
according  to  the  dispersion  required,  and  there  is  facility 
for  increasing  the  train  to  three  or  four  half-prisms,  though 
the  dispersion  with  two  only  is  nearly  double  of  that  given 
by  the  large  ten-prism  Spectroscope.  The  definition  in  this 
form  of  Spectroscope  appears  to  be  very  fine. — At  the  end  of 
May  1876,  spectroscopic  determinations  of  the  Sun's  rotation 
were  made  by  observations  of  the  relative  displacement  of 
the  Fraunhofer  lines  at  the  east  and  west  limbs  respectively. 
The  results  are  in  close  agreement  with  the  value  of  the 
rotation  found  from  observations  of  Sun-spots.  A  similar 


AT   GREENWICH   OBSERVATORY— 1876  TO    1 88 1.        319 

determination  has  also  been  made  in  the  case  of  Jupiter,  with 
equally  satisfactory  results. — An  Electrometer  on  Sir  William 
Thomson's  plan,  for  continuous  photographic  registration  of 
atmospheric  electricity  has  been  received  from  Mr  White  of 
Glasgow.     It  was  mounted  in  December. — The  computation 
of  the  photographic  records  of  the  barometer  from  1854  to 
1873  has  so  far  advanced  that  we  can  assert  positively  that 
there  is  no  trace  of  lunar  tide  in  the  atmosphere  ;  but  that 
there  is  a  strongly  marked  semi-diurnal  solar  tide,  accom- 
panied   with    a   smaller   diurnal    tide.      We   are   at   present 
engaged    in    comparing   the   barometric    measures   with   the 
directions  of  the  wind. — Regarding  the  distribution  of  the 
printed  observations  :  There  is  no  extensive  wish  for  separate 
magnetic  observations,  but  general  magnetic  results  are  in 
great  demand,  especially  for  mining  operations,  and  to  meet 
this  a  map  of  magnetic  declination  is  furnished  in  the  news- 
paper called  the  '  Colliery  Guardian.' — As  regards  the  opera- 
tions for  the  Transit  of  Venus  :  The  computing  staff  has  by 
degrees  been  reduced  to  two  junior  computers   within    the 
Observatory ;    and  one  or   two   computers   external   to   the 
Observatory,  who  are  employed  on  large  groups  of  systematic 
calculations.     The  principal  part  of  the  calculations  remaining 
at  the  date  of  the  last  Report  was  that  applying  to  the  deter- 
mination   of   the    geographical    longitudes    of   fundamental 
stations.     At  the  moment  of  my  writing,  the  last  of  these 
(the  longitude  of  Observatory  Bay,  Kerguelen)  is  not  abso- 
lutely  finished: The    method  of  determining  the   geo- 
graphical longitude  of  the  principal  station  in  each  group  by 
vertical  transits  of  the  Moon  has  been  found  very  successful 
at    Honolulu    and    Rodriguez.     For   stations    in   high  south 
latitude,  horizontal  transits  are  preferable. — As  regards  the 
Numerical    Lunar   Theory:    With    the   view   of   preserving, 
against  the  ordinary  chances  of  destruction  or  abandonment, 
a  work  which  is  already  one  of  considerable  magnitude,  I 
have  prepared  and  have  printed  as  Appendix  to  the  Green- 
wich Observations  (with  additional  copies  as  for  a  separate 


32O  GEORGE   BIDDELL  AIRY. 

work)  the  ordinary  Equations  of  Lunar  Disturbance,  the 
novel  theory  of  Symbolical  Variations,  and  the  Numerical 
Developments  of  the  quantities  on  the  first  side  of  the 
Equations. — At  various  times  from  February  to  May  I  was 
engaged  on  the  reduction  of  Malta  Tides,  and  on  a  Paper 
concerning  the  same. — In  July  I  was  awarded  the  Albert 
Medal  for  my  Compass  corrections,  and  received  the  same 
from  the  Prince  of  Wales. — In  February,  Campbell's  instru- 
ment for  the  registration  of  sunshine  was  introduced :  it  was 
mounted  in  July." 

Of  private  history:  "I  was  at  Playford  until  Jan.  iQth,  in 
close  correspondence  as  usual  with  Mr  Christie  at  the  Obser- 
vatory, and  attending  to  my  Numerical  Lunar  Theory. — 
From  Mar.  2Qth  to  Apr.  2nd  I  went  on  a  short  trip  to  Here- 
ford, Worcester,  &c.  —  From  June  8th  to  2Oth  I  was  at 
Playford. — From  Aug.  I3th  to  Sept.  8th  Airy  was  on  an 
expedition  in  Ireland,  chiefly  in  the  North  and  West,  with 
his  daughters.  When  at  Dublin  he  visited  Grubb's  instru- 
ment factory.  On  the  return  journey  he  stayed  for  some 
time  in  the  Lake  District  of  Cumberland,  and  took  soundings 
in  the  neighbourhood  of  the  place  of  the  '  floating  island '  in 
Derwentwater." 

Airy  took  the  greatest  interest  in  antiquarian  matters, 
whether  military  or  ecclesiastical,  and  his  feelings  on  such 
matters  is  well  illustrated  by  the  following  letter  : 


ROYAL  OBSERVATORY,  GREENWICH,  S.E. 
1877,  February  27. 

DEAR  SIR, 

I  venture  to  ask  if  you  can  assist  me  in  the  following 
matter. 

In  the  Parish  Church  of  Playford,  near  Ipswich,  Suffolk,  was  a 
splendid  brass  tombstone  to  -Sir  Thomas  Felbrigg.  By  an  act  of 
folly  and  barbarism,  almost  unequalled  in  the  history  of  the  world, 
the  Incumbent  and  Curate  nearly  destroyed  the  brass  inscription 
surrounding  the  image  of  the  Knight. 


AT   GREENWICH   OBSERVATORY — 1876  TO    1 88 1.        321 

This  tombstone  is  figured  in  Cough's  Sepulchral  Antiquities, 
which,  I  presume,  is  to  be  found  in  the  British  Museum. 

And  I  take  the  liberty  to  ask  if  you  would  kindly  look  at  the 
engraving,  and  give  me  any  suggestion  as  to  the  way  in  which  some 
copies  of  it  could  be  made,  in  a  fairly  durable  form.  I  am  connected 
with  the  parish  of  Playford,  and  am  anxious  to  preserve  for  it  this 
memorial  of  a  family  of  high  rank  formerly  resident  there. 

I  am,  dear  Sir, 

Very  faithfully  yours, 

G.  B.  AIRY. 
T.  Winter  Jones,  Esq. 

To  this  request  Mr  Winter  Jones  immediately  acceded, 
and  the  engraving  was  duly  photographed,  and  copies  were 
circulated  with  a  historical  notice  of  Sir  George  (not  Sir 
Thomas)  Felbrigg  and  a  history  of  the  Monument.  Sir 
George  Felbrigg  was  Esquire-at-Arms  to  Edward  III.,  and 
Lord  of  the  Manor  of  Playford  :  he  died  in  1400,  and  was 
buried  in  the  North  wall  of  Playford  Church. 


1878 

The  Report  to  the  Board  of  Visitors  has  this  paragraph  : 
"  I  continue  to  remark  the  approaching  necessity  for  Library 
extension.  Without  having  absolutely  decided  on  a  site,  I 
may  suggest  that  I  should  wish  to  erect  a  brick  building, 
about  50  feet  by  20,  consisting  of  two  very  low  stones  (or 
rather  of  one  story  with  a  gallery  running  round  its  walls),  so 
low  that  books  can  be  moved  by  hand  without  necessity  for  a 
ladder. — In  the  month  of  December,  1877,  the  azimuthal 
error  of  the  Transit  Circle  had  increased  to  10".  A  skilful 
workman,  instructed  by  Mr  Simms,  easily  reduced  the  error 
to  about  2" *5  (which  would  leave  its  mean  error  nearly  o), 
the  western  Y  being  moved  to  the  north  so  far  as  to  reduce 
the  reading  of  the  transit  micrometer,  when  pointed  to  the 
south,  from  3 5 r> 500  to  35r>ooo.  The  level  error  was  not  sen- 
sibly affected. — The  Sidereal  Standard  Clock  preserves  a  rate 

A.   B.  21 


322  GEORGE   BIDDELL  AIRY. 

approaching  to  perfection,  so  long  as  it  is  left  without  dis- 
turbance of  the  galvanic-contact  springs  (touched  by  its  pen- 
dulum), which  transmit  signals  at  every  second  of  time  to 
sympathetic  clocks  and  the  chronograph.  A  readjustment 
of  these  springs  usually  disturbs  the  rate. — To  facilitate  the 
observations  of  stars,  a  new  working  catalogue  has  been 
prepared,  in  which  are  included  all  stars  down  to  the  third 
magnitude,  stars  down  to  the  fifth  magnitude  which  have  not 
been  observed  in  the  last  two  catalogues,  and  a  list  of  258 
stars  of  about  the  sixth  magnitude  of  which  the  places  are 
required  for  the  United  States  Coast  Survey.  The  whole 
number  of  stars  in  our  new  working  list  is  about  2500.  It 
may  be  here  mentioned  that  an  extensive  series  of  observa- 
tions was  made,  during  the  autumn,  of  about  70  stars,  at  the 
request  of  Mr  Gill,  for  comparison  with  Mars,  Ariadne,  and 
Melpomene. — On  Apr.  loth  last,  a  very  heavy  fall  of  rain 
took  place.  Between  Apr.  lod.  5h.  and  Apr.  lid.  2h., 
2*824  inch.  was  recorded,  and  75  per  cent,  of  this,  or  2*12  inch., 
fell  in  the  eight  hours  between  13!  h.  and  21 J  h. ;  and  on 
May  7,  I  inch  of  rain  fell  in  50  minutes,  of  which  J  inch  fell 
in  15  minutes. — The  supplementary  compensation  continues 
to  be  applied  with  success  to  Government  chronometers 
which  offer  facilities  for  its  introduction,  and  a  marked  im- 
provement in  the  performance  of  chronometers  returned  after 
repair  by  the  makers  appears  to  have  resulted  from  the 
increased  attention  now  given  to  the  compensation.  Of  the 
29  competitive  chronometers,  25  have  the  supplementary 
compensation." — With  regard  to  the  reduction  of  the  observa- 
tions of  the  Transit  of  Venus  :  After  reference  to  the  diffi- 
culties arising  from  the  errors  and  the  interpretation  of  the 
language  used  by  some  of  the  observers,  the  Report  con- 
tinues thus  :  "Finally  a  Report  was  made  to  the  Government 
on  July  5th,  giving  as  the  mean  result  for  Mean  Solar 
Parallax  8" "76";  the  results  from  ingress  and  from  egress, 
however,  differing  to  the  extent  of  o"*i  I.... After  further 
examination  and  consideration,  the  result  for  parallax  has 


AT   GREENWICH   OBSERVATORY — 1876   TO    l88l.        323 

been  increased  to  8"' 82  or  8"'83.  The  results  from  photo- 
graphy have  disappointed  me  much.  The  failure  has  arisen, 
perhaps  sometimes  from  irregularity  of  limb,  or  from  atmo- 
spheric distortion,  but  more  frequently  from  faintness  and 
from  want  of  clear  definition.  Many  photographs,  which  to 
the  eye  appeared  good,  lost  all  strength  and  sharpness  when 
placed  under  the  measuring  microscope.  A  final  result  8"'  17 
was  obtained  from  Mr  Burton's  measures,  and  8"*o8  from 
Capt.  Tupman's. — With  regard  to  the  Numerical  Lunar 
Theory :  A  cursory  collection  of  the  terms  relating  to  the 
Areas  (in  the  Ecliptic)  led  me  to  suppose  that  there  might 
be  some  error  in  the  computations  of  the  Annual  Equation 
and  related  terms.  A  most  jealous  re-examination  has  how- 
ever detected  nothing,  and  has  confirmed  my  belief  in  the 
general  accuracy  of  the  numerical  computations.  I  dare  not 
yet  venture  to  assume  an  error  in  Delaunay's  theory;  but  I 
remember  that  the  Annual  Equation  gave  great  trouble  to 
the  late  Sir  John  Lubbock,  and  that  he  more  than  once 
changed  his  conclusions  as  to  its  true  value. —  In  February  I 
was  engaged  on  the  drawings  and  preparations  for  my 
intended  Lecture  at  Cockermouth  on  the  probable  condition 
of  the  interior  of  the  Earth.  The  Lecture  was  delivered  in 
April. — At  different  times  in  the  autumn  I  was  engaged  on 
diagrams  to  illustrate  the  passage  of  rays  through  eye-pieces 
and  double-image  micrometers. — The  miscellaneous  scientific 
correspondence,  which  was  always  going  on,  was  in  this  year 
unusually  varied  and  heavy." 

Of  private  history  :  He  was  at  Playford  till  Jan.  26th. — 
In  April  he  went  to  Cockermouth  to  deliver  his  Lecture 
above-mentioned :  the  journey  was  by  Birmingham,  where 
he  stayed  for  two  days  (probably  with  his  son  Osmund,  who 
resided  there),  to  Tarn  Bank  (the  residence  of  Isaac  Fletcher, 
M.P.) :  the  lecture  was  delivered  on  the  22nd :  he  made 
excursions  to  Thirlmere  and  Barrow,  and  to  Edward  I.'s 
Monument,  and  returned  to  Greenwich  on  the  27th. — From 
June  1 7th  to  28th  he  was  at  Playford. — From  Aug.  igth  to 

21 — 2 


324  GEORGE   BIDDELL   AIRY. 

Sept.  1 7th  he  was  travelling  in  Scotland,  visiting  the  Tay 
Bridge,  the  Loch  Katrine  Waterworks,  &c.,  and  spent  the 
last  fortnight  of  his  .trip  at  Portinscale,  near  Keswick.  On 
Dec.  23rd  he  went  to  Playforct. 


1879 

"  The  manuscripts  of  every  kind,  which  are  accumulated 
in  the  ordinary  transactions  of  the  Observatory,  are  preserved 
with  the  same  care  and  arranged  on  the  same  system  as 
heretofore.  The  total  number  of  bound  volumes  exceeds 
4000.  Besides  these  there  is  the  great  mass  of  Transit  of 
Venus  reductions  and  manuscripts,  which  when  bound  may 
be  expected  to  form  about  200  volumes. — With  regard  to  the 
numerous  group  of  Minor  Planets,  the  Berlin  authorities  have 
most  kindly  given  attention  to  my  representation,  and  we 
have  now  a  most  admirable  and  comprehensive  Ephemeris. 
But  the  extreme  faintness  of  the  majority  of  these  bodies 
places  them  practically  beyond  the  reach  of  our  meridian 
instrument,  and  the  difficulty  of  observation  is  in  many  cases 
further  increased  by  the  large  errors  of  the  predicted  places. — 
After  a  fine  autumn,  the  weather  in  the  past  winter  and 
spring  has  been  remarkably  bad.  More  than  an  entire 
lunation  was  lost  with  the  Transit  Circle,  no  observation  of 
the  Moon  on  the  meridian  having  been  possible  between 
January  8  and  March  I,  a  period  of  more  than  seven  weeks. 
Neither  Sun  nor  stars  were  visible  for  eleven  days,  during 
which  period  the  clock-times  were  carried  on  entirely  by  the 
preceding  rate  of  the  clock.  The  accumulated  error  at  the 
end  of  this  time  did  not  exceed  os>3. — Some  difficulty  was  at 
first  experienced  with  the  Thomson  Electrometer,  which  was 
traced  to  want  of  insulation.  This  has  been  mastered  by  the 
use  of  glass  supporters,  which  carry  some  sulphuric  acid. 
The  instrument  is  now  in  excellent  order,  and  the  photo- 
graphic registers  have  been  perfectly  satisfactory  since  1879, 


AT  GREENWICH   OBSERVATORY — 1876  TO    1 88 1.        325 

February,  when  the  new  insulators  were  applied. — From  the 
annual  curves  of  diurnal  inequality,  deduced  from  the  Mag- 
netic Reductions,  most  important  inferences  may  be  drawn, 
as  to  the  connection  between  magnetic  phenomena  and  sun- 
spots.  These  annual  curves  shew  a  well-marked  change  in 
close  correspondence  with  the  number  of  sun-spots.  About 
the  epoch  of  maximum  of  sun-spots  they  are  large  and  nearly 
circular,  having  the  same  character  as  the  curves  for  the 
summer  months  ;  whilst  about  the  time  of  sun-spot  minimum 
they  are  small  and  lemniscate-shaped,  with  a  striking  resem- 
blance to  the  curves  for  the  winter  months.  The  connection 
between  changes  of  terrestrial  magnetism  and  sun-spots  is 
shewn  in  a  still  more  striking  manner  by  a  comparison  which 
Mr  Ellis  has  made  between  the  monthly  means  of  the  diurnal 
range  of  declination  and  horizontal  force,  and  Dr  R.  Wolf's 
'relative  numbers'  for  frequency  of  sun-spots. — The  records 
of  sunshine  with  Campbell's  Registering  Sun-dial  are  pre- 
served in  a  form  easily  accessible  for  reference,  and  the  results 
are  communicated  weekly  to  the  Agricultural  Gazette. — Prof. 
Oppolzer's  results  for  the  determination  of  the  longitudes  of 
Vienna  and  Berlin,  made  in  1877,  have  now  been  made 
public.  They  shew  a  remarkable  agreement  of  the  Chrono- 
metric  determination  formerly  made  with  the  Telegraphic. 
It  may  be  of  interest  to  recall  the  fact  that  a  similar  agree- 
ment was  found  between  the  Chronometric  and  Telegraphic 
determinations  of  the  longitude  of  Valentia. — For  observing 
the  Transit  of  Venus  of  1882,  the  general  impression  appears 
to  be  that  it  will  be  best  to  confine  our  observations  to  simple 
telescopic  observations  or  micrometer  observations  at  Ingress 
and  Egress,  if  possible  at  places  whose  longitudes  are  known. 
For  the  first  phenomenon  (accelerated  ingress)  the  choice  of 
stations  is  not  good ;  but  for  the  other  phenomena  (retarded 
ingress,  accelerated  egress,  retarded  egress)  there  appears  to 
be  no  difficulty. — With  regard  to  the  Numerical  Lunar 
Theory  :  Respecting  the  discordance  of  Annual  Equation, 
I  suspend  my  judgment  I  have  now  discussed  the  theory 


326  GEORGE    BIDDELL  AIRY. 

completely ;  and  in  going  into  details  of  secular  changes,  I 
am  at  this  time  engaged  on  that  which  is  the  foundation  of 
all,  namely,  the  change  of  excentricity  of  the  Solar  Orbit, 
and  its  result  in  producing  Lurfar  Acceleration.  An  import- 
ant error  in  the  theoretical  formulae  for  Variations  of  Radius 
Vector,  Longitude,  and  Latitude,  was  discovered  ;  some  cal- 
culations depending  on  them  are  cancelled." — Referring  to  the 
magnitude  of  the  printed  volume  of  "Greenwich  Observa- 
tions," and  the  practicability  of  reducing  the  extent  of  it, 
the  Report  states  thus :  "  The  tendency  of  external  scientific 
movement  is  to  give  great  attention  to  the  phenomena  of  the 
Solar  disc  (in  which  this  Observatory  ought  undoubtedly  to 
bear  its  part).  And  I  personally  am  most  unwilling  to  recede 
from  the  existing  course  of  magnetical  and  meteorological 
observations.... The  general  tendency  of  these  considerations 
is  to  increase  the  annual  expenses  of  the  Observatory.  And 
so  it  has  been,  almost  continuously,  for  the  last  42  years. 
The  annual  ordinary  expenses  are  now  between  2\  and  3 
times  as  great  as  in  my  first  years  at  the  Royal  Observatory. 
\/  — Mr  Gill  was  appointed  to  the  Cape  Observatory,  and  I 
wrote  out  instructions  for  him  in  March  :  there  was  subse- 
quently much  correspondence  respecting  the  equipment  and 
repairs  of  the  Cape  Observatory." — In  the  Monthly  Notices  of 
the  Royal  Astronomical  Society  for  January  an  article  had 
appeared  headed  "  Notes  on  the  late  Admiral  Smyth's  Cycle 
of  Celestial  Objects,  Vol.  II."  by  Mr  Herbert  Sadler.  In  this 
article  Mr  Sadler  had  criticized  the  work  of  Admiral  Smyth 
in  a  manner  which  Airy  regarded  as  imputing  bad  faith  to 
Admiral  Smyth.  He  at  once  took  up  the  defence  of  his  old 
friend  very  warmly,  and  proposed  certain  Drafts  of  Resolu- 
tions to  the  Council  of  the  Society.  These  Resolutions  were 
moved,  but  were  amended  or  negatived,  and  Airy  immediately 
resigned  his  office  of  Vice-President.  There  was  considerable 
negociation  on  the  subject,  and  discussion  with  Lord  Lindsay, 
and  on  May  Qth  Airy's  Resolutions  were  accepted  by  the 
Council. — In  October  Airy  inspected  the  "  Faraday  "  tele- 


AT   GREENWICH   OBSERVATORY — 1 8/6   TO    1 88 1.        327 

graph  ship,  then  lying  in  the  river  near  Messrs  Siemens' 
works,  and  broke  his  finger  by  a  fall  on  board  the  vessel. — In 
this  year  Airy  wrote  and  circulated  a  letter  to  the  Members 
of  the  Senate  of  the  University  of  Cambridge,  on  the  subject 
of  the  Papers  set  in  the  Smith's  Prizes  Examination.  In  this 
letter,  as  on  former  occasions,  he  objected  much  to  the  large 
number  of  questions  in  "  purely  idle  algebra,  arbitrary  combi- 
nations of  symbols,  applicable  to  no  further  purpose."  And 
in  particular  he  singled  out  for  comment  the  following  ques- 
tion, which  was  one  of  those  set,  "  Using  the  term  circle  as 
extending  to  the  case  where  the  radius  is  a  pure  imaginary, 
it  is  required  to  construct  the  common  chord  of  two  given 
circles."  This  drew  forth  as  usual  a  rejoinder  from  Prof. 
Cayley,  who  wrote  enclosing  a  solution  of  his  problem,  but 
not  at  all  to  Airy's  satisfaction,  who  replied  as  follows :  "  I  am 
not  so  deeply  plunged  in  the  mists  of  impossibles  as  to  appre- 
ciate fully  your  explanation  in  this  instance,  or  to  think  that 
it  is  a  good  criterion  for  University  candidates." 

Of  private  history:  On  Jan.  2ist  he  returned  from  Play- 
ford. — On  March  22nd  he  attended  the  funeral  of  his  sister  at 
Little  Welnetham  near  Bury  St  Edmunds :  Miss  Elizabeth 
Airy  had  lived  with  him  at  the  Observatory  from  shortly 
after  his  appointment. — For  about  a  week  at  the  end  of  April 
he  was  visiting  Matlock,  Edensor,  and  Buxton. — From  June 
1 4th  to  July  1 8th  he  was  staying  at  Portinscale  near 
Keswick. — He  was  at  Playford  for  two  or  three  days  in 
October,  and  went  there  again  on  Dec.  23rd  for  his  usual 
winter  holiday. 

The  following  letter,  relating  to  the  life  of  Thomas  Clark- 
son,  was  written  to  Dr  Merivale,  Dean  of  Ely,  after  reading 
the  account  in  the  "  Times"  of  October  loth  of  the  unveiling 
of  a  statue  of  Clarkson  near  Ware  : 


328  GEORGE   BIDDELL   AIRY. 


ROYAL  OBSERVATORY,  GREENWICH, 

LONDON,  S.E. 
4*.^  £  1879,  October  11. 

DEAR  SIR, 

Pardon  my  intrusion  on  you,  in  reference  to  a  transaction 
which  has  greatly  interested  me — the  honour  paid  by  you  to  the 
memory  of  Thomas  Clarkson.  With  very  great  pleasure  I  have  heard 
of  this  step :  and  I  have  also  been  much  satisfied  with  the  remarks 
on  it  in  the  "Times."  I  well  remember,  in  Clarkson's  "History  of 
the  Abolition,"  which  I  read  some  60  years  ago,  the  account  of  the 
circumstance,  now  commemorated  by  you,  which  determined  the 
action  of  his  whole  subsequent  life. 

It  is  not  improbable  that,  among  those  who  still  remember 
Clarkson,  my  acquaintance  with  him  began  at  the  earliest  time  of 
all.  I  knew  him,  intimately,  from  the  beginning  of  1815  to  his 
death.  The  family  which  he  represented  must  have  occupied  a  very 
good  position  in  society.  I  have  heard  that  he  sold  two  good 
estates  to  defray  the  expenses  which  he  incurred  in  his  personal 
labours  for  Abolition  :  and  his  brother  was  Governor  of  Sierra  Leone 
(I  know  not  at  what  time  appointed).  Thomas  Clarkson  was  at  St 
John's  College;  and,  as  I  gather  from  circumstances  which  I  have 
heard  him  mention,  must  have  been  a  rather  gay  man.  He  kept  a 
horse,  and  at  one  time  kept  two.  He  took  Orders  in  the  Church ; 
and  on  one  occasion,  in  the  course  of  his  Abolition  struggle,  he 
preached  in  a  church.  But  he  afterwards  resolutely  laid  aside  all 
pretensions  to  the  title  of  Minister  of  the  Church,  and  never  would 
accept  any  title  except  as  layman.  He  was,  however,  a  very  earnest 
reader  of  theology  during  my  acquaintance  with  him,  and  appeared 
to  be  well  acquainted  with  the  Early  Fathers. 

The  precise  words  in  which  was  announced  the  subject  for  Prize 
Essay  in  the  University  were  "Anne  liceat  invitos  in  servitutem 
trahere." 

After  the  first  great  victory  on  the  slave  trade  question,  he  estab- 
lished himself  in  a  house  on  the  bank  of  Ullswater.  I  have  not 
identified  the  place :  from  a  view  which  he  once  shewed  me  I  sup- 
posed it  to  be  near  the  bottom  of  the  lake :  but  from  an  account  of 
the  storm  of  wind  which  he  encountered  when  walking  with  a  lady 
over  a  pass,  it  seemed  to  be  in  or  near  Patterdale.  When  the 
remains  of  a  mountaineer,  who  perished  in  Helvellyn  (as  described 


AT   GREENWICH   OBSERVATORY — 1876  TO    1 88 1.        329 

in  Scott's  well-known  poem),  were  discovered  by  a  shepherd,  it  was 
to  Mr  Clarkson  that  the  intelligence  was  first  brought. 

He  then  lived  at  Bury  St  Edmunds.  Mrs  Clarkson  was  a  lady 
of  Bury.  But  I  cannot  assign  conjecturally  any  dates  to  his  removals 
or  his  marriage.  His  only  son  took  his  B.A.  degree,  I  think,  about 
1817. 

I  think  it  was  in  1814  that  he  began  his  occupation  of  Play  ford 
Hall — a  moated  mansion  near  Ipswich,  formerly  of  great  import- 
ance— where  he  lived  as  Gentleman  Farmer,  managing  a  farm  leased 
from  the  Marquis  of  Bristol,  and  occupying  a  good  position  among 
the  gentry  of  the  county.  A  relative  of  mine,  with  whom  I  was 
most  intimately  acquainted,  lived  in  the  same  parish  (where  in 
defiance  of  school  rules  I  spent  nearly  half  my  time,  to  my  great 
advantage  as  I  believe,  and  where  I  still  retain  a  cottage  for  occa- 
sional residence),  and  I  enjoyed  much  of  Mr  Clarkson's  notice.  It 
was  by  his  strong  advice  that  I  was  sent  to  Cambridge,  and  that 
Trinity  College  was  selected:  he  rode  with  me  to  Rev.  Mr  Rogers 
of  Sproughton  for  introductory  examination ;  he  introduced  me  to 
Rev.  C.  Musgrave  (subsequently  of  Halifax),  accidentally  doing  duty 
at  Grundisburgh,  who  then  introduced  me  to  Sedgwick,  Peacock, 
and  T.  Musgrave  (subsequently  of  York).  In  1825,  when  I  spent  the 
summer  at  Keswick,  he  introduced  me  to  Southey  and  Wordsworth. 

Mr  Clarkson  lived  about  thirty  years  at  Playford  Hall,  and  died 
there,  and  lies  interred  with  his  wife,  son,  and  grandson,  in  Playford 
churchyard.  I  joined  several  friends  in  erecting  a  granite  obelisk  to 
his  memory  in  the  same  churchyard.  His  family  is  extinct :  but  a 
daughter  of  his  brother  is  living,  first  married  to  T.  Clarkson's  son, 
and  now  Mrs  Dickinson,  of  the  Rectory,  Wolferton. 

I  am,  my  dear  Sir, 

Very  faithfully  yours, 

G.    B.   AIRY. 

The  Very  Reverend, 

The  Dean  of  Ely. 


1880 

"  The  Admiralty,  on  final  consideration  of  the  estimates, 
decided  not  to  proceed  with  the  erection  of  a  new  Library 


33°  GEORGE   BIDDELL   AIRY. 

near  the  Magnetic  Observatory  in  the  present  year.  In  the 
mean  time  the  space  has  been  cleared  for  the  erection  of  a 
building  50  by  20  feet. — I  have  removed  the  Electrometer 
Mast  (a  source  of  some  'expense*  and  some  danger),  the  per- 
fect success  of  Sir  William  Thomson's  Electrometer  rendering 
all  further  apparatus  for  the  same  purpose  unnecessary. — 
Many  years  ago  a  double-image  micrometer,  in  which  the 
images  were  formed  by  the  double  refraction  of  a  sphere  of 
quartz,  was  prepared  by  Mr  Dollond  for  Capt.  Smyth,  R.N. 
Adopting  the  same  principle  on  a  larger  scale,  I  have  had 
constructed  by  Mr  Hilger  a  micrometer  with  double  refrac- 
tion of  a  sphere  of  Iceland  spar.  Marks  have  been  prepared 
for  examination  of  the  scale,  but  I  have  not  yet  had  oppor- 
tunity of  trying  it. — The  spectroscopic  determination  of  Star- 
motions  has  been  steadily  pursued.  The  stars  are  taken 
from  a  working  list  of  150  stars,  which  may  eventually  be 
extended  to  include  all  stars  down  to  the  fourth  magnitude, 
and  it  is  expected  that  in  the  course  of  time  the  motions  of 
about  300  stars  may  be  spectroscopically  determined. — A 
new  pressure-plate  with  springs  has  been  applied  by  Mr 
Browning  to  Osier's  Anemometer,  and  it  is  proposed  to  make 
such  modification  as  will  give  a  scale  extending  to  5olbs. 
pressure  on  the  square  foot.  Other  parts  of  the  instrument 
have  also  been  renewed. — As  regards  the  reduction  of  the 
magnetical  results  since  1863  :  In  the  study  of  the  forms  of 
the  individual  curves ;  their  relations  to  the  hour,  the  month, 
the  year ;  their  connection  with  solar  or  meteorological  facts ; 
the  conjectural  physico-mechanical  causes  by  which  they  are 
produced  ;  there  is  much  to  occupy  the  mind.  I  regret  that, 
though  in  contemplation  of  these  curves  I  have  remarked 
some  singular  (but  imperfect)  laws,  I  have  not  been  able  to 
pursue  them. — The  mean  temperature  of  the  year  1879  was 
46*1°,  being  3*3°  below  the  average  of  the  preceding  38  years. 
The  highest  temperature  was  80*6°  on  July  30,  and  the  lowest 
137°  on  Dec.  7.  The  mean  temperature  was  below  the 
average  in  every  month  of  the  year ;  the  months  of  greatest 


AT  GREENWICH   OBSERVATORY — 1876  TO    1 88 1.        331 

deviation  being  January  and  December,  respectively  6'8°  and 
7*6°  below  the  average  ;  the  months  of  April,  May,  July,  and 
November  were  each  between  4°  and  5°  below  the  average. 
The  number  of  hours  of  bright  sunshine,  recorded  with 
Campbell's  Sunshine  Instrument,  during  1879,  was  only 
983. — In  the  summer  of  1879  Commander  Green,  U.S.N., 
came  over  to  this  country  for  the  purpose  of  determining 
telegraphically  the  longitude  of  Lisbon,  as  part  of  a  chain  of 
longitudes  extending  from  South  America  to  Greenwich.  A 
successful  interchange  of  signals  was  made  with  Commander 
Green  between  Greenwich  and  Porthcurno  on  four  nights, 
1879,  June  25  to  29.  The  results  communicated  by  Com- 
mander Green  shew  that  the  longitude  of  Lisbon  Observatory, 
as  adopted  in  the  Nautical  Almanac,  requires  the  large 
correction  of  +  8'548. — With  regard  to  the  coming  Transit  of 
Venus  in  1882  :  From  the  facility  with  which  the  requirements 
for  geographical  position  are  satisfied,  and  from  the  rapid  and 
accurate  communication  of  time  now  given  by  electric  tele- 
graph, the  observation  of  this  Transit  will  be  comparatively 
easy  and  inexpensive.  I  have  attached  greater  importance 

than  I  did  formerly  to  the  elevation  of  the  Sun I  remark 

that  it  is  highly  desirable  that  steps  be  taken  now  for  deter- 
mining by  telegraph  the  longitude  of  some  point  of  Australia. 
I  have  stated  as  the  general  opinion  that  it  will  be  useless 
to  repeat  photographic  observations. — In  April  Mr  Barlow 
called,  in  reference  to  the  Enquiry  on  the  Tay  Bridge  Disaster. 
(The  Bridge  had  been  blown  down  on  Dec.  28th,  1879.)  I 
prepared  a  memorandum  on  the  subject  for  the  Tay  Bridge 
Commission,  and  gave  evidence  in  a  Committee  Room  of  the 
House  of  Lords  on  Apr.  29th."  (Much  of  the  Astronomer 
Royal's  evidence  on  this  occasion  had  reference  to  the 
opinions  which  he  had  expressed  concerning  the  wind- 
pressure  which  might  be  expected  on  the  projected  Forth 
Bridge,  in  1873.) — In  May  Airy  was  consulted  by  the  Post- 
master-General in  the  matter  of  a  dispute  which  had  arisen 
between  the  Post  Office  and  the  Telephone  Companies,  which 


332  GEORGE   BIDDELL   AIRY. 

latter  were  alleged  to  have  infringed  the  monopoly  of  the 
Post  Office  in  commercial  telegraphs  :  Airy  made  a  declara- 
tion on  the  subject. — In  July  Mr  Bakhuyzen  came  to  England 
to  determine  the  longitude  of*  Leyden,  on  which  he  was 
engaged  till  Sept.  9th.  and  carried  on  his  observations  at 
the  Observatory. — In  July  Airy  was  much  engaged  in 
perusing  the  records  of  Mr  Gill's  work  at  the  Cape  of  Good 
Hope. 

Of  private  history :  On  Jan.  24th  he  returned  from  Play- 
ford. — From  June  I4th  to  July  4th  he  was  again  at  Playford. 
— From  September  2ist  to  October  2oth  he  was  staying  at 
Portinscale  near  Keswick. — On  Dec.  23rd  he  went  again  to 
Playford  for  his  winter  holiday. 

Respecting  the  agitation  at  Cambridge  for  granting 
University  degrees  to  women,  the  following  extract  from  a 
letter  addressed  to  a  young  lady  who  had  forwarded  a 
Memorial  on  the  subject  for  his  consideration,  and  dated 
Nov.  loth,  1880,  contains  Airy's  views  on  this  matter. 

"  I  have  not  signed  the  Memorial  which  you  sent  for  my  con- 
sideration: and  I  will  endeavour  to  tell  you  why.  I  entirely  approve 
of  education  of  young  women  to  a  higher  pitch  than  they  do  com- 
monly reach.  I  think  that  they  can  successfully  advance  so  far  as 
to  be  able  clearly  to  understand — with  gratification  to  themselves 
and  with  advantage  to  those  whose  education  they  will  superintend — 
much  of  the  results  of  the  highest  class  of  science  which  have  been 
obtained  by  men  whose  lives  are  in  great  measure  devoted  to  it. 
But  I  do  not  think  that  their  nature  or  their  employments  will 
permit  of  their  mastering  the  severe  steps  of  beginning  (and  indeed 
all  through)  and  the  complicated  steps  at  the  end.  And  I  think  it 
well  that  this  their  success  should  be  well  known — as  it  is  sure  to  be 
— among  their  relatives,  their  friends,  their  visitors,  and  all  in  whom 
they  are  likely  to  take  interest.  Their  connection  with  such  a  place 
as  Girton  College  is  I  think  sufficient  to  lead  to  this.  But  I  desire 
above  all  that  all  this  be  done  in  entire  subservience  to  what  I 
regard  as  infinitely  more  valuable  than  any  amount  of  knowledge, 
namely  the  delicacy  of  woman's  character.  And  here,  I  think,  our 
views  totally  separate.  I  do  not  imagine  that  the  University  Degree 
would  really  imply,  as  regards  education,  anything  more  than  is 


AT   GREENWICH   OBSERVATORY — 1876   TO    1 88 1.        333 

known  to  all  persons  (socially  concerned  in  the  happiness  of  the 
young  woman)  from  the  less  public  testimonial  of  the  able  men  who 
have  the  means  of  knowing  their  merits.  And  thus  it  appears  to  me 
that  the  admission  to  University  Degree  would  simply  mean  a  more 
extended  publication  of  their  names.  I  dread  this." 


1881 

"  The  new  line  of  underground  telegraph  wires  has  been 
completed  by  the  officers  of  the  General  Post  Office.  The 
new  route  is  down  Groom's  Hill  in  Greenwich,  and  the  result 
of  this  change,  at  least  as  regards  the  earth-current  wires,  and 
probably  as  regards  the  other  wires,  has  not  been  satisfactory. 
It  was  soon  found  that  the  indications  of  the  earth-current 
wires  were  disturbed  by  a  continual  series  of  petty  fluctua- 
tions which  almost  completely  masked  the  proper  features  of 

earth  currents If  this  fault  cannot  be  removed,  I  should 

propose  to  return  to  our  original  system  of  independent  wires 
(formerly  to  Croydon  and  Dartford). — The  new  Azimuth- 
mark  (for  the  Altazimuth),  upon  the  parapet  of  the  Naval 
College,  is  found  to  be  perfectly  satisfactory  as  regards  both 
steadiness  and  visibility.  The  observations  of  a  low  star  for 
zero  of  azimuth  have  been  omitted  since  the  beginning  of 
1 88 1  ;  the  mark,  in  combination  with  a  high  star,  appearing 
to  give  all  that  is  necessary  for  this  purpose. — All  the  instru- 
ments have  suffered  from  the  congealing  of  the  oil  during  the 
severe  weather  of  the  past  winter,  and  very  thorough  cleaning 
of  all  the  moving  parts  has  been  necessary. — The  Solar 
Eclipse  of  1880,  Dec.  31,  was  well  observed.  The  first  contact 
was  observed  by  four  observers  and  the  last  contact  by  two. 
The  computations  for  the  observations  have  been  excep- 
tionally heavy,  from  the  circumstance  that  the  Sun  was  very 
low  (86°  1 4'  Z.  D.  at  the  last  observation)  and  that  it  has 
therefore  been  necessary  to  compute  the  refraction  with  great 
accuracy,  involving  the  calculation  of  the  zenith  distance  for 


334  GEORGE   BIDUELL  AIRY. 


every  observation.  And  besides  this,  eighty-six  separate 
computations  of  the  tabular  R.  A.  and  N.  P.  D.  of  cusps  have 
been  required.  —  Amongst  other  interesting  spectroscopic 
observations  of  the  Sun,  a  remarkable  spectrum  of  a  sun-spot 
shewing  17  strong  black  lines  or  bands,  each  as  broad  as  b^ 
in  the  solar  spectrum,  was  observed  on  1880,  Nov.  27  and  29. 
These  bands  to  which  there  is  nothing  corresponding  in  the 
Solar  Spectrum  (except  some  very  faint  lines)  have  also  been 
subsequently  remarked  in  the  spectrum  of  several  spots. — 
The  Police  Ship  '  Royalist '  (which  was  injured  by  a  collision 
in  1879  and  had  been  laid  up  in  dock)  has  not  been  again 
moored  in  the  river,  and  the  series  of  observations  of  the 
temperature  of  the  Thames  is  thus  terminated. — Part  of  the 
month  of  January  1881  was,  as  regards  cold,  especially  severe. 
The  mean  temperature  of  the  period  January  12  to  26  (15 
days)  was  only  24'2°,  or  147°  below  the  average ;  the 
temperature  fell  below  20°  on  10  days,  and  rose  above  the 
freezing  point  only  on  3  days.  The  highest  temperature  in 
this  period  was  35'3°,  the  lowest  127°.  On  January  I7th 
(while  staying  at  Playford)  my  son  Hubert  and  I  noticed  an 
almost  imperceptible  movement  in  the  upper  clouds  from  the 
South- East.  On  that  night  began  the  terrible  easterly  gale, 
accompanied  with  much  snow,  which  lasted  to  the  night  of 
the  1 8th.  The  limiting  pressure  of  50  Ibs.  on  the  square 
foot  of  Osier's  Anemometer  was  twice  exceeded  during  this 
storm. — With  respect  to  the  Diurnal  Inequalities  of  Magnetic 
Horizontal  Force :  Assuming  it  to  be  certain  that  they 
originate  from  the  Sun's  power,  not  immediately,  but 
mediately  through  his  action  on  the  Earth,  it  appears  to 
me  (as  I  suggested  long  ago)  that  they  are  the  effects  of 
the  attraction  of  the  red  end  or  north  end  of  the  needle  by  the 
heated  portions  of  our  globe,  especially  by  the  heated  sea, 
whose  effect  appears  to  predominate  greatly  over  that  of 
the  land.  I  do  not  say  that  everything  is  thus  made  perfectly 
clear,  but  I  think  that  the  leading  phenomena  may  be  thus 
explained.  And  this  is  almost  necessarily  the  way  of 


AT  GREENWICH   OBSERVATORY — 1 8/6   TO    1 88 1.       335 


beginning  a  science. —  In  the  first  few  years  after  the  strict 
and  systematic  examination  of  competitive  chronometers, 
beginning  with  1856,  the  accuracy  of  chronometers  was 
greatly  increased.  For  many  years  past  it  has  been  nearly 
stationary.  I  interpret  this  as  shewing  that  the  effects  of  bad 
workmanship  are  almost  eliminated,  and  that  future  improve- 
ment must  be  sought  in  change  of  some  points  of  construction. 
— Referring  to  the  Transit  of  Venus  in  1874,  the  printing  of  all 
sections  of  the  Observations,  with  specimens  of  the  printed 
forms  employed,  and  remarks  on  the  photographic  operations, 
is  very  nearly  completed.  An  Introduction  is  begun  in 
manuscript.  I  am  in  correspondence  with  the  Commission 
which  is  entrusted  with  the  arrangements  for  observation  of 
the  Transit  of  1882. — The  Numerical  Lunar  Theory  has  been 
much  interrupted  by  the  pressure  of  the  Transit  of  Venus 
work  and  other  business." — In  his  Report  to  the  Board  of 
Visitors  (his  46th  and  last),  Airy  remarks  that  it  would  be  a 
fitting  opportunity  for  the  expression  of  his  views  on  the 
general  objects  of  the  Observatory,  and  on  the  duties  which 
they  impose  on  all  who  are  actively  concerned  in  its  conduct. 
And  this  he  proceeds  to  do  in  very  considerable  detail. — On 
May  5th  he  wrote  to  Lord  Northbrook  (First  Lord  of  the 
Admiralty)  and  to  Mr  Gladstone  to  resign  his  post  of 
Astronomer  Royal.  From  time  to  time  he  was  engaged  on 
the  subject  of  a  house  for  his  future  residence,  and  finally 
took  a  lease  of  the  White  House  at  the  top  of  Groom's  Hill, 
just  outside  one  of  the  gates  of  Greenwich  Park.  On  the 
1 5th  of  August  he  formally  resigned  his  office  to  Mr  W.  H.  M. 
Christie,  who  had  been  appointed  to  succeed  him  as  Astrono- 
mer Royal,  and  removed  to  the  White  House  on  the  next  day, 
August  1 6th. 

His  holiday  movements  in  the  portion  of  the  year  up  to 
August  1 6th  consisted  in  his  winter  visit  to  Playford,  from 
which  he  returned  on  Jan.  24th  :  and  a  subsequent  visit  to 
Playford  from  June  7th  to  i8th. 


336  GEORGE   BIDDELL  AIRY. 

The  following  correspondence  relating  to  Airy's  retirement 
from  office  testifies  in  a  remarkable  manner  to  the  estimation 
in  which  his  services  were  held,  and  to  the  good  feeling  which 
subsisted  between  him  and  his  Official  superiors. 

10,  DOWNING  STREET,  WHITEHALL, 
June  6,  iS8i. 

DEAR  SIR  GEORGE  AIRY, 

I  cannot  receive  the  announcement  of  your  resig- 
nation, which  you  have  just  conveyed  to  me,  without  expressing  my 
strong  sense  of  the  distinction  you  have  conferred  upon  the  office  of 
Astronomer  Royal,  and  of  the  difficulty  of  supplying  your  place  with 
a  person  of  equal  eminence.  Let  me  add  the  expression  of  my  best 
wishes  for  the  full  enjoyment  of  your  retirement  from  responsibility. 

I  remain,  dear  Sir  George  Airy, 
Faithfully  yours, 

W.  E.  GLADSTONE. 


ADMIRALTY, 
June  loth,  1881. 
SIR, 

I  am  commanded  by  my  Lords  Commissioners  of  the  Admi- 
ralty to  acknowledge  the  receipt  of  your  letter  of  the  4th  instant, 
intimating  your  desire  to  retire  on  the  i5th  August  next  from  the 
office  of  Astronomer  Royal. 

2.  In   reply  I  am  to  acquaint  you  that  your  wishes  in  this 
matter  have  been  communicated  to  the  Prime  Minister,  and  that  the 
further  necessary  official  intimation  will  in  due  course  be  made  to 
the  Treasury. 

3.  At  the  same  time  I  am  instructed  by  their  Lordships  to 
convey  to  you    the   expression   of  their  high  appreciation  of  the 
remarkably   able   and   gifted    manner,    combined    with    unwearied 
diligence  and  devotion  to  the  Public  Service  (especially  as  regards 
the  Department  of  the  State  over  which  they  preside),  in  which  you 
have  performed  the  duties  of  Astronomer  Royal  throughout  the  long 
period  of  forty-five  years. 

4.  I  am  further  to  add  that  their  Lordships  cannot  allow  the 
present  opportunity  to  pass  without  giving  expression  to  their  sense 


AT   GREENWICH   OBSERVATORY — 1876  TO    l88l.        337 

of  the  loss  which  the  Public  Service  must  sustain  by  your  retirement, 
and  to  the  hope  that  you  may  long  enjoy  the  rest  to  which  you  are 
so  justly  entitled. 

I  am,  Sir, 

Your  obedient  Servant, 

ROBERT  HALL. 
Sir  G.  B.  Airy,  K.C.B. 

&>c.,          &>c., 
Royal  Observatory,   Greenwich. 


ADMIRALTY, 
28/7*  June,  1 88 1. 
SIR, 

My  Lords  Commissioners  of  the  Admiralty  have  much 
pleasure  in  transmitting  copy  of  a  resolution  passed  by  the  Board  of 
Visitors  of  the  Royal  Observatory  on  the  4th  June  last,  bearing 
testimony  to  the  valuable  services  you  have  rendered  to  Astronomy, 
to  Navigation,  and  the  allied  Sciences  throughout  the  long  period 
during  which  you  have  presided  over  the  Royal  Observatory. 

I  am,  Sir, 

Your  obedient  Servant, 

ROBERT  HALL. 
Sir  George  Biddell  Airy,  K.C.B. 

6°<r.,         &c.y         &c., 
Royal  Observatory,  Greenwich. 

"  The  Astronomer  Royal  (Sir  George  B.  Airy)  having  an- 
nounced his  intention  of  shortly  retiring  from  his  position  at 
the  Royal  Observatory,  the  following  resolution  proposed  by 
Professor  J.  C.  Adams,  and  seconded  by  Professor  G.  G. 
Stokes,  was  then  unanimously  adopted  and  ordered  to  be 
recorded  in  the  Minutes  of  the  Proceedings. 

"The  Board  having  heard  from  the  Astronomer  Royal 
that  he  proposes  to  terminate  his  connection  with  the  Ob- 
servatory on  the  1 5th  of  August  next,  desire  to  record  in  the 
most  emphatic  manner  their  sense  of  the  eminent  services 

A.  B.  22 


338  GEORGE  BIDDELL  AIRY. 

which  he  has  rendered  to  Astronomy,  to  Navigation  and  the 
allied  Sciences,  throughout  the  long  period  of  45  years  during 
which  he  has  presided  over  the  Royal  Observatory. 

"They  consider  that  during  that  time  he  has  not  only 
maintained  but  has  greatly  extended  the  ancient  reputation 
of  the  Institution,  and  they  believe  that  the  Astronomical  and 
other  work  which  has  been  carried  on  in  it  under  his  direction 
will  form  an  enduring  monument  of  his  Scientific  insight  and 
his  powers  of  organization. 

"  Among  his  many  services  to  Science,  the  following  are  a 
few  which  they  desire  especially  to  commemorate  : 

(a)  "  The  complete  re-organization  of  the  Equipment  of 
the  Observatory. 

(b)  "The  designing  of  instruments  of  exceptional  sta- 
bility and  delicacy  suitable  for  the  increased  accuracy  of  ob- 
servation demanded  by  the  advance  of  Astronomy. 

(c)  "  The  extension  of  the  means  of  making  observations 
of  the  Moon  in  such  portions  of  her  orbit  as  are  not  accessible 
to  the  Transit  Circle. 

(d)  "  The  investigation  of  the  effect  of  the  iron  of  ships 
upon    compasses   and    the   correction   of   the   errors   thence 
arising. 

(e)  "The   Establishment  at  the  Observatory  and  else- 
where of  a  System  of  Time  Signals  since  extensively  de- 
veloped by  the  Government. 

"  The  Board  feel  it  their  duty  to  add  that  Sir  George  Airy 
has  at  all  times  devoted  himself  in  the  most  unsparing 
manner  to  the  business  of  the  Observatory,  and  has  watched 
over  its  interests  with  an  assiduity  inspired  by  the  strongest 
personal  attachment  to  the  Institution.  He  has  availed  him- 
self zealously  of  every  scientific  discovery  and  invention  which 
was  in  his  judgment  capable  of  adaptation  to  the  work  of  the 
Observatory ;  and  the  long  series  of  his  annual  reports  to  the 
Board  of  Visitors  furnish  abundant  evidence,  if  such  were 
needed,  of  the  soundness  of  his  judgment  in  the  appreciation 
of  suggested  changes,,  and  of  his  readiness  to  introduce  im- 


AT   GREENWICH   OBSERVATORY — 1 876  TO    1 88 1.        339 

provements  when  the  proper  time  arrived.  While  maintain- 
ing the  most  remarkable  punctuality  in  the  reduction  and 
publication  of  the  observations  made  under  his  own  superin- 
tendance,  he  had  reduced,  collected,  and  thus  rendered  avail- 
able for  use  by  astronomers,  the  Lunar  and  Planetary  Obser- 
vations of  his  predecessors.  Nor  can  it  be  forgotten  that, 
notwithstanding  his  absorbing  occupations,  his  advice  and 
assistance  have  always  been  at  the  disposal  of  Astronomers 
for  any  work  of  importance. 

"  To  refer  in  detail  to  his  labours  in  departments  of 
Science  not  directly  connected  with  the  Royal  Observatory 
may  seem  to  lie  beyond  the  province  of  the  Board.  But  it 
cannot  be  improper  to  state  that  its  members  are  not  un- 
acquainted with  the  high  estimation  in  which  his  contribu- 
tions to  the  Theory  of  Tides,  to  the  undulatory  theory  of 
Light,  and  to  various  abstract  branches  of  Mathematics  are 
held  by  men  of  Science  throughout  the  world. 

"  In  conclusion  the  Board  would  express  their  earnest 
hope,  that  in  his  retirement  Sir  George  Airy  may  enjoy 
health  and  strength  and  that  leisure  for  which  he  has  often 
expressed  a  desire  to  enable  him  not  only  to  complete  the 
numerical  Lunar  Theory  on  which  he  has  been  engaged  for 
some  years  past,  but  also  to  advance  Astronomical  Science 
in  other  directions." 


ADMIRALTY, 
2-jth  October,  1881. 
SIR, 

I  am  commanded  by  my  Lords.  Commissioners  of  the  Ad- 
miralty to  transmit  to  you,  herewith,  a  copy  of  a  Treasury  Minute, 
awarding  you  a  Special  Pension  of  ^uoo  a  year,  in  consideration 
of  your  long  and  brilliant  services  as  Astronomer  Royal. 

I  am,  Sir, 

Your  obedient  Servant, 

ROBERT  HALL. 

Sir  G.  B.  Airy,  K.C.B.,  RR.S.,  6-v.,  &f. 
The  White  House^  Groom's  Hill,  Greenwich, 

22 2 


340  GEORGE   BIDDELL  AIRY. 

Copy  of  Treasury  Minute,  dated  loth  October,  1881  : 

My  Lords  have  before  them  a  statement  of  the  services  of  Sir 
George  Biddell  Airy,  K.-C.B.,  F.R.S.,  who  has  resigned  the  appoint- 
ment of  Astronomer  Royal  on  th£  ground  of  age. 

Sir  George  Airy  has  held  his  office  since  the  year  1835,  and 
has  also,  during  that  period,  undertaken  various  laborious  works, 
demanding  scientific  qualifications  of  the  highest  order,  and  not 
always  such  as  could  strictly  be  said  to  be  included  among  the  duties 
of  his  office. 

The  salary  of  Sir  G.  Airy  as  Astronomer  Royal  is  .£1200  a  year, 
in  addition  to  which  he  enjoys  an  official  residence  rent  free,  and, 
under  ordinary  circumstances  he  would  be  entitled  to  a  pension 
equal  to  two-thirds  of  his  salary  and  emoluments. 

My  Lords,  however,  in  order  to  mark  their  strong  sense  of  the 
distinction  which,  during  a  long  and  brilliant  career  Sir  George  Airy 
has  conferred  upon  his  office,  and  of  the  great  services  which,  in 
connection  with,  as  well  as  in  the  discharge  of,  his  duties,  he  has 
rendered  to  the  Crown  and  the  Public,  decide  to  deal  with  his  case 
under  the  ixth  Section  of  the  Superannuation  Act,  1859,  which 
empowers  them  to  grant  a  special  pension  for  special  services. 

Accordingly   my   Lords   are  pleased   to   award   to   Sir   George 
Biddell  Airy,  K.C.B.,  F.R.S.,  a  special  Retired  Allowance  of 
per  annum. 


THE  WHITE  HOUSE, 
GROOM'S  HILL,  GREENWICH, 

1 88 1,  October  29. 
SIR, 


I  have  the  honour  to  acknowledge  your  letter  of  October  27, 
transmitting  to  me,  by  instruction  of  The  Lords  Commissioners  of 
Admiralty,  copy  of  a  Treasury  Minute  dated  1881  October  10,  in 
which  the  Lords  Commissioners  of  Her  Majesty's  Treasury  are 
pleased  to  award  to  me  an  annual  retired  allowance  of  ^"iioo  per 
annum. 

Acknowledging  the  very  liberal  award  of  the  Lords  Commis- 
sioners of  Treasury,  and  the  honourable  and  acceptable  terms  in 
which  it  is  announced,  I  take  leave  at  the  same  time  to  offer  to 


AT   GREENWICH   OBSERVATORY — 1876   TO    1 88 1.        341 

Their  Lordships  of  the  Admiralty  my  recognition  of  Their  Lordships' 
kindness  and  courtesy  in  thus  handing  to  me  copy  of  the  Treasury 
Minute. 

I  have  the  honour  to  be,  Sir, 

Your  very  obedient  Servant, 

G.    B.   AIRY. 
The  Secretary  of  the  Admiralty. 


From  the  Assistants  of  the  Royal  Observatory,  with 
whom  he  was  in  daily  communication,  whose  faithful  and 
laborious  services  he  had  so  often  thankfully  recognized  in 
his  Annual  Reports  to  the  Board  of  Visitors,  and  to  whom  so 
much  of  the  credit  and  success  of  the  Observatory  was  due, 
he  received  the  following  address  : 

ROYAL  OBSERVATORY,  GREENWICH, 
1 88 1,  August  ii. 

DEAR  SIR, 

We  cannot  allow  the  official  relation  which  has  so  long 
existed  between  yourself  and  us  to  terminate  without  expressing  to 
you  our  sense  of  the  admirable  manner  in  whicfr  you  have,  in  our 
opinion,  upheld  the  dignity  of  the  office  of  Astronomer  Royal 
during  the  many  years  that  you  have  occupied  that  important  post. 

Your  long  continued  and  varied  scientific  work  has  received 
such  universal  recognition  from  astronomers  in  all  lands,  that  it  is 
unnecessary  for  us  to  do  more  than  assure  you  how  heartily  we  join 
in  their  appreciation  of  your  labours.  We  may  however  add  that 
our  position  has  given  us  opportunities  of  seeing  that  which  others 
cannot  equally  well  know,  the  untiring  energy  and  great  industry 
which  have  been  therein  displayed  throughout  a  long  and  laborious 
career,  an  energy  which  leads  you  in  retirement,  and  at  fourscore 
years  of  age,  to  contemplate  further  scientific  work. 

We  would  ask  you  to  carry  with  you  into  private  life  the  best 
wishes  of  each  one  of  us  for  your  future  happiness,  and  that  of  your 
family,  expressing  the  hope  that  the  days  of  retirement  may  not  be 


342  GEORGE   BIDDELL  AIRY. 


few,  and   assuring  you  that  your  name  will  long  live  in  our  re- 
membrance. 

We  are,  dear.  Sir, 

Yours  very  faithfully, 

W.  H.  M.  CHRISTIE,  EDWIN  DUNKIN,  WILLIAM 
ELLIS,  GEORGE  STRICKLAND  CRISWICK,  W. 
C.  NASH,  A.  M.  W.  DOWNING,  EDWARD  W. 
MAUNDER,  W.  G.  THACKERAY,  THOMAS  LEWIS. 

Sir  G.  B.  Airy,  K.C.B.,  &c.,  &v., 
Astronomer  Royal. 


ROYAL  OBSERVATORY,  GREENWICH, 
1 88 1,  August  13. 

MY  DEAR  MR  CHRISTIE, 

and  Gentlemen  of  the  Royal  Observatory, 

With  very  great  pleasure  I  have  received 

your  letter  of  August  n.  I  thank  you  much  for  your  recognition 
of  the  general  success  of  the  Observatory,  and  of  a  portion  of  its 
conduct  which — as  you  remark — can  scarcely  be  known  except  to 
those  who  are  every  day  engaged  in  it :  but  I  thank  you  still  more 
for  the  kind  tone  of  your  letter,  which  seems  to  shew  that  the  terms 
on  which  we  have  met  are  such  as  leaves,  after  so  many  years' 
intercourse,  no  shadow  of  complaint  on  any  side. 

Reciprocating  your  wishes  for  a  happy  life,  and  in  your  case  a 
progressive  and  successful  one, 

I  am, 

My  dear  Mr  Christie  and  Gentlemen, 
Yours  faithfully, 

G.    B.    AIRY. 


Throughout  his  tenure  of  office  Airy  had  cultivated  and 
maintained  the  most  friendly  relations  with  foreign  astrono- 
mers, to  the  great  advantage  of  the  Observatory.  Probably 


AT  GREENWICH  OBSERVATORY— 1876  TO    1 88 1.        343 

all  of  them,  at  one  time  or  another,  had  visited  Greenwich, 
and  to  most  of  them  he  was  well  known.  On  his  retirement 
from  office  he  received  an  illuminated  Address  from  his 
old  friend  Otto  Struve  and  the  staff  of  the  Pulkowa  Observa- 
tory, an  illuminated  Address  from  the  Vorstand  of  the 
Astronomische  Gesellschaft  at  Berlin  signed  by  Dr  Auwers 
and  the  Secretaries,  a  complimentary  letter  from  the 
Academy  of  Sciences  at  Amsterdam,  and  friendly  letters  of 
sympathy  from  Dr  Gould,  Prof.  Newcombe,  Dr  Listing,  and 
from  many  other  scientific  friends  and  societies.  His  replies 
to  the  Russian  and  German  Addresses  were  as  follows : 

ROYAL  OBSERVATORY,  GREENWICH, 
1 88 1,  Augtist  5. 

MY  DEAR  SIR, 

I  received,  with  feelings  which  I  will  not  attempt 
to  describe,  the  Address  of  yourself  and  the  Astronomers  of  Pul- 
kowa generally,  on  the  occasion  of  my  retirement  from  the  office 
of  Astronomer  Royal.  I  can  scarcely  credit  myself  with  possessing 
all  the  varied  claims  to  your  scientific  regard  which  you  detail.  I 
must  be  permitted  to  attribute  many  of  them  to  the  long  and 
warm  friendship  which  has  subsisted  so  long  between  the  Directors 
of  the  Pulkowa  Observatory  and  myself,  and  which  has  influenced 
the  feelings  of  the  whole  body  of  Astronomers  attached  to  that 
Institution.  On  one  point,  however,  I  willingly  accept  your  favour- 
able expressions — I  have  not  been  sparing  of  my  personal  labour — 
and  to  this  I  must  attribute  partial  success  on  some  of  the  subjects 
to  which  you  allude. 

In  glancing  over  the  marginal  list  of  scientific  pursuits,  I  remark 
with  pleasure  the  reference  to  Optics.  I  still  recur  with  delight  to 
the  Undulatory  Theory,  once  the  branch  of  science  on  which  I  was 
best  known  to  the  world,  and  which  by  calculations,  writings,  and 
lectures,  I  supported  against  the  Laplacian  School.  But  the  close 
of  your  remarks  touches  me  much  more — the  association  of  the 
name  of  W.  Struve  and  my  own.  I  respected  deeply  the  whole 
character  of  your  Father,  and  I  believe  that  he  had  confidence  in 
me.  From  our  first  meeting  in  1830  (on  a  Commission  for  im- 
provement of  the  Nautical  Almanac)  I  never  ceased  to  regard  him 
as  superior  to  others.  I  may  be  permitted  to  add  that  the  delivery 


344  GEORGE   BIDDELL  AIRY. 

of  his  authority  to  the  hands  of  his  son  has  not  weakened  the  con- 
nection of  myself  with  the  Observatory  of  Poulkova. 

Acknowledging  gratefully  your  kindness,  and  that  of  all  the 
Astronomers  of  the  Observatory?'*of  Poulkova,  and  requesting  you 
to  convey  to  them  this  expression, 

I  am,  my  dear  ^ir, 

Yours  most  truly, 

G.  B.  AIRY. 

To  M.  Otto  von  Struve, 

Director  of  the  Observatory  of  Poulkova 
and  the  Astronomers  of  that  Observatory. 


ROYAL  OBSERVATORY,  GREENWICH, 
1 88 1,  August  3. 

MY  DEAR  SIR, 

With  very  great  pleasure  I  received  the  Address  of 
the  Astronomische  Gesellschaft  on  occasion  of  my  intended  resigna- 
tion of  the  Office  of  Astronomer  Royal:  dated  July  27,  and  signed 
by  yourself  as  President  and  Messrs  Schoenfeld  and  Winnecke  as 
Secretaries  of  the  Astronomische  Gesellschaft.  I  thank  you  much 
for  the  delicacy  of  your  arrangement  for  the  transmission  of  this 
document  by  the  hands  of  our  friend  Dr  Huggins.  And  I  think 
you  will  be  gratified  to  learn  that  it  arrived  at  a  moment  when  I 
was  surrounded  by  my  whole  family  assembled  at  my  jour-de-fete, 
and  that  it  added  greatly  to  the  happiness  of  the  party. 

I  may  perhaps  permit  myself  to  accept  your  kind  recognition  of 
my  devotion  of  time  and  thought  to  the  interests  of  my  Science  and 
my  Office.  It  is  full  reward  to  me  that  they  are  so  recognized. 
As  to  the  success  or  utility  of  these  efforts,  without  presuming, 
myself,  to  form  an  opinion,  I  acknowledge  that  the  connection 
made  by  the  Astronomische  Gesellschaft,  between  my  name  and 
the  advance  of  modern  astronomy,  is  most  flattering,  and  will  always 
be  remembered  by  me  with  pride. 

It  is  true,  as  is  suggested  in  vour  Address,  that  one  motive  for 
my  resignation  of  Office  was  the  desire  to  find  myself  more  free 


AT   GREENWICH   OBSERVATORY — 1876  TO    1 88 1.        345 

for  the  prosecution  of  further  astronomical  investigations.  Should 
my  health  remain  unbroken,  I  hope  to  enter  shortly  upon  this 
undertaking. 

Again  acknowledging  the  kindness  of  yourself  and  the  Vorstand 
of  the  Astronomische  Gesellschaft,  and  offering  my  best  wishes  for 
the  continued  success  of  that  honourable  institution, 

I  am,  my  dear  Sir, 

Yours  very  truly, 

G.  B.  AIRY. 
To  Dr  Auwers 

and  the  Vorstand  of  the 
Astronomische  Gesellschaft. 


CHAPTER   X. 

AT  THE  WHITE  HOUSE,  GREENWICH.  FROM  HIS  RESIG- 
NATION OF  OFFICE  ON  AUGUST  ISTH,  1881,  TO  HIS 
DEATH  ON  JANUARY  2ND,  1892. 

HISTORY  OF  HIS  LIFE  AFTER  HIS  RESIGNATION  OF 

OFFICE. 

ON  the  i6th  of  August  1881  Airy  left  the  Observatory 
which  had  been  his  residence  for  nearly  46  years,  and  re- 
moved to  the  White  House.  Whatever  his  feelings  may  have 
been  at  the  severing  of  his  old  associations  he  carefully  kept 
them  to  himself,  and  entered  upon  his  new  life  with  the 
cheerful  composure  and  steadiness  of  temper  which  he  pos- 
sessed in  a  remarkable  degree.  He  was  now  more  than 
80  years  old,  and  the  cares  of  office  had  begun  to  weigh 
heavily  upon  him :  the  long-continued  drag  of  the  Transit 
of  Venus  work  had  wearied  him,  and  he  was  anxious  to 
carry  on  and  if  possible  complete  his  Numerical  Lunar 
Theory,  the  great  work  which  for  some  years  had  occu- 
pied much  of  his  time  and  attention.  His  mental  powers 
were  still  vigorous,  and  his  energy  but  little  impaired :  his 
strong  constitution,  his  regular  habits  of  life,  the  systematic 
relief  which  he  obtained  by  short  holiday  expeditions  when- 
ever he  found  himself  worn  with  work,  and  his  keen  interest 
in  history,  poetry,  classics,  antiquities,  engineering,  and  other 
subjects  not  immediately  connected  with  his  profession,  had 
combined  to  produce  this  result.  And  in  leaving  office,  he 
had  no  idea  of  leaving  off  work ;  his  resignation  of  office 
merely  meant  for  him  a  change  of  work.  It  is  needless  to 


AT  THE  WHITE   HOUSE,   GREENWICH.  347 

say  that  his  interest  in  the  welfare  and  progress  of  the 
Observatory  was  as  keen  as  ever  ;  his  advice  was  always 
at  the  service  of  his  successor,  and  his  appointment  as 
Visitor  a  year  or  two  after  his  resignation  gave  him  an 
official  position  with  regard  to  the  Observatory  which  he 
much  valued.  The  White  House,  which  was  to  be  his 
home  for  the  rest  of  his  life,  is  just  outside  one  of  the 
upper  gates  of  the  Park,  and  about  a  quarter  of  a  mile 
from  the  Observatory.  Here  he  resided  with  his  two  un- 
married daughters.  The  house  suited  him  well  and  he  was 
very  comfortable  there :  he  preferred  to  live  in  the  neigh- 
bourhood with  which  he  was  so  familiar  and  in  which  he 
was  so  well  known,  rather  than  to  remove  to  a  distance. 
His  daily  habits  of  life  were  but  little  altered  :  he  worked 
steadily  as  formerly,  took  his  daily  walk  on  Blackheath, 
made  frequent  visits  to  Playford,  and  occasional  expedi- 
tions to  the  Cumberland  Lakes  and  elsewhere. 

The  work  to  which  he  chiefly  devoted  himself  in  his 
retirement  was  the  completion  of  his  Numerical  Lunar 
Theory.  This  was  a  vast  work,  involving  the  subtlest  con- 
siderations of  principle,  very  long  and  elaborate  mathe- 
matical investigations  of  a  high  order,  and  an  enormous 
amount  of  arithmetical  computation.  The  issue  of  it  was 
unfortunate :  he  concluded  that  there  was  an  error  in  some 
of  the  early  work,  which  vitiated  the  results  obtained  :  and 
although  the  whole  process  was  published,  and  was  left  in 
such  a  state  that  it  would  be  a  comparatively  simple  task 
for  a  future  astronomer  to  correct  and  complete  it,  yet  it 
was  not  permitted  to  the  original  author  of  it  to  do  this. 
To  avoid  the  necessity  of  frequent  reference  to  this  work 
in  the  history  of  Airy's  remaining  years,  it  will  be  con- 
venient to  summarize  it  here.  It  was  commenced  in  1872  : 
"On  Feb.  23rd  in  this  year  I  first  (privately)  formed  the 
notion  of  preparing  a  Numerical  Lunar  Theory  by  substi- 
tuting Delaunay's  numbers  in  the  proper  Equations  and 
seeing  what  would  come  of  it."  From  this  time  forward 


348  GEORGE   BIDDELL   AIRY. 

till  his  power  to  continue  it  absolutely  failed,  he  pursued 
the  subject  with  his  usual  tenacity  of  purpose.  During  his 
tenure  of  office  every  available  opportunity  was  seized  for 
making  progress  with  his  Lunar  Theory,  and  in  every  Report 
to  the  Visitors  a  careful  statement  was  inserted  of  the  state 
in  which  it  then  stood.  And,  after  his  resignation  of  office, 
it  formed  the  bulk  of  his  occupation.  In  1873  the  Theory 
was  formed,  and  by  1874  it  was  so  far  advanced  that  he 
published  in  the  Monthly  Notices  of  the  Royal  Astronomical 
Society  a  statement  of  the  fundamental  points  of  the  Theory. 
In  1875,  the  Theory  having  advanced  to  a  stage  where  ex- 
tensive arithmetical  computation  was  required,  he  obtained 
a  small  grant  from  the  Government  in  aid  of  the  expense 
of  the  work,  and  other  grants  were  made  in  subsequent 
years.  By  1878  the  calculations  were  so  far  advanced  that 
an  opinion  could  be  formed  as  to  the  probable  accuracy  of 
the  Theory,  and  the  following  remark  is  made:  "A  cursory 
collation  of  the  terms  relating  to  the  Areas  (in  the  Ecliptic) 
led  me  to  suppose  that  there  might  be  some  error  in  the 
computations  of  the  Annual  Equation  and  related  terms;" 
but  no  error  could  be  discovered  and  the  work  proceeded. 
The  complex  character  of  the  Theory,  and  the  extreme  care 
required  in  the  mathematical  processes,  are  well  illustrated 
by  the  following  statement,  which  occurs  in  the  Report  of 
1879,  "An  important  error  in  the  theoretical  formulae  for 
Variations  of  Radius  Vector,  Longitude,  and  Latitude,  was 
discovered ;  some  calculations  depending  on  them  are  can- 
celled." In  1880  and  1881  the  work  was  continued,  but  was 
"  sadly  interrupted  by  the  pressure  of  the  Transit  of  Venus 
work  and  other  business."  After  his  resignation  of  the  Office 
of  Astronomer  Royal  he  had  no  further  public  assistance, 
and  did  much  of  the  computations  himself,  but  a  sum  of 
,£100  was  contributed  by  Mr  De  La  Rue  in  furtherance  of 
the  work,  and  this  sum  was  spent  on  computers.  In  his 
retirement  the  work  made  good  progress,  and  on  Dec.  3ist, 
1882,  he  made  the  following  note:  "I  finished  and  put  in 


AT   THE   WHITE    HOUSE,   GREENWICH.  349 

general   order  the  final  tables  of  Equations  of  Variations. 

This   is  a  definite  point  in  the    Lunar  Theory I    hope 

shortly  to  take  up  severely  the  numerical  operations  of  the 
Lunar  Theory  from  the  very  beginning."  The  work  was 
continued  steadily  through  1883,  and  on  Mar.  24th,  1884,  he 
made  application  through  the  Board  of  Visitors  to  the  Ad- 
miralty to  print  the  work :  after  the  usual  enquiries  as  to 
the  expense  this  was  acceded  to,  and  copy  was  sent  to  the 
printers  as  soon  as  it  was  ready.  The  first  printed  proofs 
were  received  on  Feb.  5th,  1885,  and  the  whole  book  was 
printed  by  the  end  of  1886.  From  the  frequent  references 
in  his  journal  to  errors  discovered  and  corrected  during  the 
progress  of  these  calculations,  it  would  seem  likely  that  his 
powers  were  not  what  they  had  been,  and  that  there  was 
a  probability  that  some  important  errors  might  escape  cor- 
rection. He  was  far  too  honest  to  blind  himself  to  this  pos- 
sibility, and  in  the  Preface  to  his  Numerical  Lunar  Theory 
he  says  thus :  "  I  have  explained  above  that  the  principle 
of  operations  was,  to  arrange  the  fundamental  mechanical 
equations  in  a  form  suited  for  the  investigations  of  Lunar 
Theory;  to  substitute  in  the  terms  of  these  equations  the 
numerical  values  furnished  by  Delaunay's  great  work ;  and 
to  examine  whether  the  equations  are  thereby  satisfied. 
With  painful  alarm,  I  find  that  they  are  not  satisfied;  and 
that  the  discordance,  or  failure  of  satisfying  the  equations, 
is  large.  The  critical  trial  depends  on  the  great  mass  of 
computations  in  Section  II.  These  have  been  made  in  du- 
plicate, with  all  the  care  for  accuracy  that  anxiety  could 
supply.  Still  I  cannot  but  fear  that  the  error  which  is  the 
source  of  discordance  must  be  on  my  part.  I  cannot  con- 
jecture whether  I  may  be  able  to  examine  sufficiently  into 
this  matter."  He  resolutely  took  in  hand  the  revision  of  his 
work,  and  continued  it  till  October  1888.  But  it  is  clear 
from  the  entries  in  his  journal  that  his  powers  were  now 
unequal  to  the  task,  and  although  from  time  to  time  he 
suspected  that  he  had  discovered  errors,  yet  it  does  not 


350  GEORGE   BIDDELL   AIRY. 


appear  that  he  determined  anything  with  certainty.  He 
never  doubted  that  there  were  important  errors  in  the 
work,  and  later  on  he  left  the  following  private  note  on 
the  subject : 

NUMERICAL  LUNAR  THEORY. 

'-1890,  Sept.  29. 

I  had  made  considerable  advance  (under  official  difficulties)  in 
calculations  on  my  favourite  Numerical  Lunar  Theory,  when  I 
discovered  that,  under  the  heavy  pressure  of  unusual  matters  (two 
Transits  of  Venus  and  some  eclipses)  I  had  committed  a  grievous 
error  in  the  first  stage  of  giving  numerical  value  to  my  Theory. 

My  spirit  in  the  work  was  broken,  and  I  have  never  heartily 
proceeded  with  it  since. 

G.  B.  AIRY. 

Probably  the  error  referred  to  here  is  the  suspected  error 
mentioned  above  in  his  Report  of  1878,  as  to  which  he  sub- 
sequently became  more  certain. 

Whatever  may  be  the  imperfections  of  the  Numerical 
Lunar  Theory,  it  is  a  wonderful  work  to  have  been  turned  out 
by  a  man  85  years  old.  In  its  idea  and  inception  it  embodies 
the  experience  of  a  long  life  actively  spent  in  practical  science. 
And  it  may  be  that  it  will  yet  fulfil  the  objects  of  its  author, 
and  that  some  younger  astronomer  may  take  it  up,  correct  its 
errors  (wherever  they  may  be),  and  fit  it  for  practical  use. 
And  then  the  labour  bestowed  upon  it  will  not  have  been 
in  vain. 

Subject  always  to  the  absorbing  occupations  of  the  Lunar 
Theory  he  amused  himself  with  reading  his  favourite  subjects 
of  History  and  Antiquities.  His  movements  during  the 
remainder  of  the  year  1881  were  as  follows:  In  September  he 
paid  a  two  days'  visit  to  Lady  Herschel  at  Hawkhurst.  From 
Oct.  4th  to  i /th  he  was  at  the  Cumberland  Lakes  and 
engaged  in  expeditions  in  the  neighbourhood.  From  Nov. 
5th  to  8th  he  was  at  Cambridge,  inspecting  Prof.  Stuart's 
workshops,  and  other  scientific  institutions.  On  Dec.  I3th 


AT   THE  WHITE   HOUSE,    GREENWICH.  351 

he  went  to  Playford. — Amongst  miscellaneous  matters  :  in 
November  he  wrote  to  Mr  Rothery  on  the  loss  of  the 
'  Teuton '  at  some  length,  with  suggestions  for  the  safer 
construction  of  such  vessels. — In  October  he  was  asked  for 
suggestions  regarding  the  establishment  of  a  "  Standard 
Time "  applicable  to  the  railway  traffic  in  the  United 
States :  he  replied  as  follows  : 

1881,  Oct.  31. 
SIR, 

I  have  to  acknowledge  your  letter  of  October  17,  introducing 
to  my  notice  the  difficulty  which  appears  to  be  arising  in  America 
regarding  a  "Standard  Time,"  for  extensive  use  throughout  N. 
America  "applicable  to  railway  traffic  only."  The  subject,  as 
including  considerations  of  convenience  in  all  the  matters  to  which 
it  applies,  is  one  of  difficulties  probably  insuperable.  The  certainty, 
however,  that  objections  may  be  raised  to  every  scheme,  renders  me 
less  timid  in  offering  my  own  remarks ;  which  are  much  at  your 
service. 

I  first  comment  upon  your  expression  of  "Standard  Time 

applicable  to  railway  traffic  only."  But  do  you  mean  this  as  affecting 
the  transactions  between  one  railway  and  another  railway,  or  as 
affecting  each  railway  and  the  local  interests  (temporal  and  others)  of 
the  towns  which  it  touches  ?  The  difference  is  so  great  that  I  should 
be  disposed  to  adopt  it  as  marking  very  strongly  the  difference  to  be 
made  between  the  practices  of  railways  among  themselves  and  the 
practices  of  railways  towards  the  public ;  and  will  base  a  system  on 
that  difference. 

As  regards  the  practices  of  railways  among  themselves  :  if  the 
various  railways  of  America  are  joined  and  inosculated  as  they  are  in 
England,  it  appears  to  me  indispensable  that  they  have  one  common 
standard  among  themselves  :  say  Washington  Observatory  time.  But 
this  is  only  needed  for  the  office-transactions  between  the  railways ; 
it  may  be  kept  perfectly  private  ;  never  communicated  to  the  public 
at  all.  And  I  should  recommend  this  as  the  first  step. 

There  will  then  be  no  difficulty  in  deducing,  from  these  private 
Washington  times,  the  accurate  local  times  at  those  stations  (whose 
longitude  is  supposed  to  be  fairly  well  known,  as  a  sailor  with  a 
sextant  can  determine  one  in  a  few  hours)  which  the  railway  authori- 
ties may  deem  worthy  of  that  honour;  generally  the  termini  of 


352  GEORGE   BIDDELL   AIRY. 

railways.  Thus  we  shall  have  a  series  of  bases  of  local  time,  of 
authoritative  character,  through  the  country. 

Of  such  bases  we  have  two,  Greenwich  and  Dublin  :  and  they 
are  separated  by  a  sea-voyage.  Ijg  the  U.S.  of  America  there  must 
be  a  greater  number,  and  probably  not  so  well  separated.  Still  it  is 
indispensable  to  adopt  such  a  system  of  local  centers. 

No  people  in  this  world  can  be  induced  to  use,  a  reckoning  which 
does  not  depend  clearly  upon  the  sun.  In  all  civilized  countries  it 
depends  (approximately)  on  the  sun's  meridian  passage.  Even  the 
sailor  on  mid-ocean  refers  to  that  phenomenon.  And  the  solar 
passage,  with  reasonable  allowance,  2om.  or  3om.  one  way  or 
another,  must  be  recognized  in  all  time-arrangements  as  giving  the 
fundamental  time.  The  only  practical  way  of  doing  this  is,  to  adopt 
for  a  whole  region  the  fundamental  time  of  a  center  of  that  region. 

And  to  this  fundamental  time,  the  local  time  of  the  railway,  as 
now  entering  into  all  the  concerns  of  life,  must  be  adapted.  A 
solicitor  has  an  appointment  to  meet  a  client  by  railway ;  a  physician 
to  a  consultation.  How  is  this  to  be  kept  if  the  railway  uses  one 
time  and  every  other  act  of  life  another  ? 

There  is  one  chain  of  circumstances  which  is  almost  peculiar — 
that  of  the  line  from  New  York  to  San  Francisco.  Here  I  would 
have  two  clocks  at  every  station  :  those  on  the  north  side  all  shewing 
San  Francisco  time,  and  those  on  the  south  all  shewing  New  York 
time.  Every  traveller's  watch  would  then  be  available  to  the  end  of 
his  journey. 

A  system,  fundamentally  such  as  I  have  sketched,  would  give 
little  trouble,  and  may  I  think  be  adopted  with  advantage. 

I  am,  Sir, 

Your  faithful  servant, 

G.  B.  AIRY. 
Mr  Edward  Barrington. 


1882 

He  returned  from  Playford  on  Jan.  17  :  his  other  move- 
ments during  the  year  were  as  follows :  from  Apr.  2/th  to 
May  nth  he  was  at  Playford  ;  and  again  from  August  1st  to 
24th.  From  Oct.  9th  to  Nov.  1st  he  was  travelling  with  his 
two  unmarried  daughters  in  the  Lake  District  of  Cumber- 


AT   THE  WHITE   HOUSE,  GREENWICH.  353 

land  :  the  journey  was  by  Furness  and  Coniston  to  Portinscale 
near  Keswick ;  on  Oct.  I3th  he  fell  and  sprained  his  ankle, 
and  his  excursions  for  the  rest  of  the  time  were  mainly  con- 
ducted by  driving.  Shortly  after  his  return,  on  Nov.  nth, 
while  walking  alone  on  Blackheath,  he  was  seized  with  a 
violent  attack  of  illness,  and  lay  helpless  for  some  time  before 
he  was  found  and  brought  home  :  he  seems  however  to  have 
recovered  to  a  great  extent  in  the  course  of  a  day  or  two,  and 
continued  his  Lunar  Theory  and  other  work  as  before.  On 
June  22nd  he  made  the  following  sad  note,  "  This  morning, 
died  after  a  most  painful  illness  my  much-loved  daughter-in- 
law,  Anna  Airy,  daughter  of  Professor  Listing  of  Gottingen, 
wife  of  my  eldest  son  Wilfrid."  In  February  he  wrote  out 
his  reminiscences  of  the  village  of  Playford  during  his  boy- 
hood. 

In  June  he  was  much  disturbed  in  mind  on  hearing  of 
some  important  alterations  made  by  the  Astronomer  Royal 
in  the  Collimators  of  the  Transit  Circle,  and  some  correspon- 
dence ensued  on  the  subject. — During  the  year  he  had  much 
correspondence  on  the  subject  of  the  subsidences  on  Black- 
heath. 

The  following  letter  was  written  in  reply  to  a  gentleman 
who  had  asked  whether  it  could  be  ascertained  by  calculation 
how  long  it  is  since  the  Glacial  Period  existed  : 

1882,  July  4. 

SIR, 

I  should  have  much  pleasure  in  fully  answering  your  questions 
of  July  3  if  I  were  able  to  do  so :  but  the  subject  really  is  very 
obscure. 

(T)  Though  it  is  recognized  that  the  glacial  period  (or  periods) 
is  late,  I  do  not  think  that  any  one  has  ventured  to  fix  upon  a  rude 
number  of  years  since  elapsed. 

(2)  We  have  no  reason  to  think  that  the  mean  distance  of  the 
earth  from  the  sun  has  sensibly  altered.  There  have  been  changes 
in  the  eccentricity  of  the  orbit  (making  the  earth's  distance  from  the 
sun  less  in  one  month  and  greater  in  the  opposite  month),  but  I  do 
not  perceive  that  this  would  explain  glaciers. 

A.  B.  23 


354  GEORGE   BIDDELL  AIRY. 

(3)  I  consider  it  to  be  certain  that  the  whole  surface  of  the 
earth,  at  a  very  distant  period,  was  very  hot,  that  it  has  cooled 
gradually,  and  (theoretically  and  imperceptibly)  is  cooling  still.  The 
glaciers  must  be  later'  than  thes,0  hot  times,  and  later  than  our  last 
.consolidated  strata :  but  this  is  nearly  all  that  I  can  say. 

I  am,  Sir,  Your  obedient  Servant, 

*-   G.  B.  AIRY. 
James  Alston,  Esq. 


1883 

From  May  2nd  to  2Qth  he  was  at  Play  ford.  From  July 
loth  to  2Oth  he  was  travelling  in  South  Wales  with  his 
daughters. — From  Oct.  loth  to  Nov.  loth  he  was  at  Play  ford. 
— Between  Nov.  2Oth  of  this  year  and  Jan.  4th  of  the  year 
1884,  he  sat  several  times  to  Mr  John  Collier  for  his  portrait : 
the  picture  was  exhibited  in  the  Academy  of  1884;  it  is  a 
most  successful  and  excellent  likeness. 

Throughout  the  year  he  was  very  busy  with  the  Numerical 
Lunar  Theory. — In  March  he  was  officially  asked  to  accept 
the  office  of  Visitor  of  the  Royal  Observatory,  which  he 
accepted,  and  in  this  capacity  attended  at  the  Annual 
Visitation  on  June  2nd,  and  addressed  a  Memorandum  to 
the  Visitors  on  the  progress  of  his  Lunar  Theory. — On 
March  I2th  he  published  in  several  newspapers  a  state- 
ment in  opposition  to  the  proposed  Braithwaite  and 
Buttermere  Railway,  which  he  considered  would  be  injurious 
to  the  Lake  District,  in  which  he  took  so  deep  an  interest. — 
In  May  he  communicated  to  "  The  Observatory  "  a  statement 
of  his  objections  to  a  Theory  advanced  by  Mr  Stone  (then 
President  of  the  Royal  Astronomical  Society)  to  account  for 
the  recognized  inequality  in  the  Mean  Motion  of  the  Moon. 
This  Theory,  on  a  subject  to  which  Airy  had  given  his 
incessant  attention  for  so  many  years,  would  naturally  receive 
his  careful  attention  and  criticism,  and  it  attracted  much 
general  notice  at  the  time. — In  December  he  wrote  to  the 


AT   THE   WHITE    HOUSE,   GREENWICH.  355 

Secretary  of  the  Royal  Astronomical  Society  his  opinion  as 
to  the  award  of  the  Medal  of  the  Society.  In  this  letter  he 
stated  the  principles  which  guided  him  as  follows  :  "  I  have 
always  maintained  that  the  award  of  the  Medal  ought  to  be 
guided  mainly  by  the  originality  of  communications  :  that  one 
advance  in  a  new  direction  ought  in  our  decision  to  outweigh 
any  mass  of  work  in  a  routine  already  established  :  and  that, 
in  any  case,  scientific  utility  as  distinguished  from  mere 
elegance  is  indispensable." — In  July  Lieut.  Pinheiro  of  the 
Brazilian  Navy  called  with  an  autograph  letter  of  introduction 
from  the  Emperor  of  Brazil.  The  Lieutenant  desired  to  make 
himself  acquainted  with  the  English  system  of  Lighthouses 
and  Meteorology,  and  Airy  took  much  trouble  in  providing 
him  with  introductions  through  which  he  received  every 
facility  for  the  thorough  accomplishment  of  his  object. — On 
Oct.  8th  he  forwarded  to  Prof.  Cayley  proofs  of  Euclid's 
Propositions  I.  47  and  III.  35  with  the  following  remarks: 
"  I  place  on  the  other  side  the  propositions  which  may  be 
substituted  (with  knowledge  of  Euclid's  VI.  book)  for  the 
two  celebrated  propositions  of  the  geometrical  books.  They 
leave  on  my  mind  no  doubt  whatever  that  they  were  invented 
as  proofs  by  ratios,  and  that  they  were  then  violently  expanded 
into  cumbrous  geometrical  proofs." — On  June  28th  he  declined 
to  sign  a  memorial  asking  for  the  interment  of  Mr  Spottis- 
woode  in  Westminster  Abbey,  stating  as  his  reason,  "  I  take 
it,  that  interment  possessing  such  a  public  character  is  a 
public  recognition  of  benefits,  political,  literary,  or  philo- 
sophical, whose  effects  will  be  great  and  durable.  Now  I 
doubt  whether  it  can  be  stated  that  Mr  Spottiswoode  had 
conferred  such  benefits  on  Society."  But  he  adds  at  length 
his  cordial  recognition  of  Mr  Spottiswoode's  scientific  services. 
— Throughout  his  life  Airy  was  a  regular  attendant  at  church, 
and  took  much  interest  in  the  conduct  of  the  Church  services. 
In  October  of  this  year  he  wrote  a  long  letter  to  the  Vicar  of 
Greenwich  on  various  points,  in  which  occurs  the  following 
paragraph  :  "  But  there  is  one  matter  in  the  present  form  of 

23 — 2 


356  GEORGE   BIDDELL  AIRY. 

the  Church  Service,  on  which  my  feeling  is  very  strong, 
namely  the  (so-called,  I  believe)  Choral  Service,  in  the 
Confession,  the  Prayer,  and  the  Creed.  I  have  long  listened 
with  veneration  to  our  noble  ^Liturgy,  and  I  have  always  been 
struck  with  the  deep  personally  religious  feeling  which  per- 
vades it,  especially  those  parts  of  it  which  are  for  '  The 
People.'  And  an  earnest  Priest,  earnestly  pressing  these 
parts  by  his  vocal  example  on  the  notice  of  the  People,  can 
scarcely  fail  to  excite  a  corresponding  earnestness  in  them. 
All  this  is  totally  lost  in  the  choral  system.  For  a  venerable 
persuasion  there  is  substituted  a  rude  irreverential  confusion 
of  voices;  for  an  earnest  acceptance  of  the  form  offered  by 
the  Priest  there  is  substituted — in  my  feeling  at  least — a 
weary  waiting  for  the  end  of  an  unmeaning  form."  He  also 
objected  much  to  singing  the  responses  to  the  Command- 
ments. 


1884 

From  Apr.  2Qth  to  May  3Oth  he  was  at  Playford,  con- 
cluding his  Journal  there  with  the  note  "  So  ends  a  plea- 
sant Vacation." — On  June  nth  he  went  to  Cambridge  and 
attended  the  Trinity  College  Commemoration  Service,  and 
dined  in  Hall. — From  Aug.  I4th  to  Sept.  nth  he  was  at 
Playford. — On  Sept.  26th  he  made  an  expedition  to  Guild- 
ford  and  Farnham. — During  this  year  he  was  closely  en- 
gaged on  the  Numerical  Lunar  Theory,  and  for  relaxation 
was  reading  theology  and  sundry  books  of  the  Old  Testa- 
ment. 

On  June  7th  he  attended  at  the  Visitation  of  the  Royal 
Observatory. — In  a  letter  written  in  April  to  Lt.-Col.  Marin- 
din,  R.A.,  on  the  subject  of  wind  pressure  there  occurs  the 
following  remark :  "  When  the  heavy  gusts  come  on,  the 
wind  is  blowing  in  directions  changing  rapidly,  but  limited 
in  extent.  My  conclusion  is  that  in  arches  of  small  extent 
(as  in  the  Tay  Bridge)  every  thing  must  be  calculated  for 


AT  THE  WHITE   HOUSE,   GREENWICH.  357 

full  pressure;  but  in  arches  of  large  extent  (as  in  the  Forth 
Bridge)  every  thing  may  be  calculated  for  small  pressure. 
And  for  a  suspension  bridge  the  pressure  is  far  less  dan- 
gerous than  for  a  stiff  arch," — In  January  he  had  some 
correspondence  with  Professor  Tyndall  on  the  Theory  of 
the  "White  Rainbow,"  and  stated  that  he  thoroughly  agreed 
with  Dr  Young's  explanation  of  this  phenomenon. — The 
following  is  extracted  from  a  letter  on  May  1st  to  his  old 
friend  Otto  Struve :  "  I  received  from  you  about  3  or  4 
weeks  past  a  sign  of  your  friendly  remembrance,  a  copy  of 
your  paper  on  the  Annual  Parallax  of  Aldebaran.  It  pleased 
me  much.  Especially  I  was  delighted  with  your  noble  re- 
tention of  the  one  equation  whose  result  differed  so  sensibly 
from  that  of  the  other  equations.  It  is  quite  possible,  even 
probable,  that  the  mean  result  is  improved  by  it.  I  have 
known  such  instances.  The  first,  which  attracted  much  at- 
tention, was  Capt.  Kater's  attempt  to  establish  a  scale  of 
longitude  in  England  by  reciprocal  observations  of  azimuth 
between  Beachy  Head  and  Dunnose.  The  result  was  evi- 
dently erroneous.  But  Colonel  Colby,  on  examination  of 
the  original  papers,  found  that  some  observations  had  been 
omitted,  as  suspicious ;  and  that  when  these  were  included  the 
mean  agreed  well  with  the  scale  of  observation  inferred  from 
other  methods." — In  a  letter  to  the  Rev.  R.  C.  M.  Rouse,  ac- 
knowledging the  receipt  of  a  geometrical  book,  there  occurs 
the  following  paragraph:  "I  do  not  value  Euclid's  Elements 
as  a  super-excellent  book  of  instruction — though  some  im- 
portant points  are  better  presented  in  it  than  in  any  other 
book  of  geometrical  instruction  that  I  have  seen.  But  I 
value  it  as  a  book  of  strong  and  distinct  reasoning,  and  of 
orderly  succession  of  reasonings.  I  do  not  think  that  there 
is  any  book  in  the  world  which  presents  so  distinctly  the  ( be- 
cause  therefore '  And  this  is  invaluable  for  the  mental 

education  of  youth." — In  May  he  was  in  correspondence  with 
Professor  Balfour  Stewart  regarding  a  projected  movement 
in  Terrestrial  Magnetism  to  be  submitted  to  the  British 


GEORGE  BIDDELL  AIRY. 


Association.  Airy  cordially  approved  of  this  movement, 
and  supported  it  to  the  best  of  his  ability,  stating  that  in 
his  opinion  what  was  mainly  wanted  was  the  collation  of 
existing  records.  —  In  January  and  February  he  was  much 
pressed  by  Prof.  Pritchard  of  Oxford  to  give  his  opinion  as 
to  the  incorrectness  of  statements  made  by  Dr  Kinns  in  his 
Lectures  on  the  Scientific  Accuracy  of  "the  Bible.  Airy 
refused  absolutely  to  take  part  in  the  controversy,  but  he 
could  not  escape  from  the  correspondence  which  the  matter 
involved  :  and  this  led  up  to  other  points  connected  with 
the  early  history  of  the  Israelites,  a  subject  in  which  he  took 
much  interest. 


1885 

From  May  4th  to  June  3rd  he  was  at  Playford. — From 
July  2nd  to  22nd  he  was  in  the  Lake  District.  The  journey 
was  by  Windermere  to  Kentmere,  where  he  made  enquiries 
concerning  the  Airy  family,  as  it  had  been  concluded  with 
much  probability  from  investigations  made  by  his  nephew, 
the  Rev.  Basil  R.  Airy,  that  the  family  was  settled  there  at 
a  very  early  date.  Some  persons  of  the  name  of  Airy  were 
still  living  there.  He  then  went  on  by  Coniston  and  Gras- 
rnere  to  Portinscale,  and  spent  the  rest  of  his  time  in  expe- 
ditions amongst  the  hills  and  visits  to  friends. —  On  July  28th 
he  went  to  Woodbridge  in  Suffolk  and  distributed  the  prizes 
to  the  boys  of  the  Grammar  School  there. — From  Oct.  9th 
to  Nov.  1 2th  he  was  again  at  Playford. — Throughout  the 
year  he  was  busily  engaged  on  the  Numerical  Lunar  Theory, 
and  found  but  little  time  for  miscellaneous  reading. 

Of  printed  papers  by  Airy  in  this  year  the  most  im- 
portant was  one  on  the  "  Results  deduced  from  the  Mea- 
sures of  Terrestrial  Magnetic  Force  in  the  Horizontal  Plane," 
&c.  This  was  a  long  Paper,  communicated  to  the  Royal 
Society,  and  published  in  the  Phil.  Trans.,  and  was  the 
last  Scientific  Paper  of  any  importance  (except  the  Volume 


AT  THE  WHITE   HOUSE,   GREENWICH.  359 

of  the  Numerical  Lunar  Theory)  in  the  long  list  of  "  Papers 
by  G.  B.  Airy."  The  preparation  of  this  Paper  took  much 
time. — Of  miscellaneous  matters :  In  May  a  Committee  of 
the  Royal  Society  had  been  appointed  to  advise  the  India 
Office  as  to  the  publication  of  Col.  J.  Herschel's  pendulum 
observations  in  India ;  and  Airy  was  asked  to  assist  the 
Committee  with  his  advice.  He  gave  very  careful  and 
anxious  consideration  to  the  subject,  and  it  occupied  much 
time. — In  the  early  part  of  the  year  he  was  asked  by  Sir 
William  Thomson  to  assist  him  with  an  affidavit  in  a  law- 
suit concerning  an  alleged  infringement  of  one  of  his  Pa- 
tents for  the  improvement  of  the  Compass.  Airy  declined 
to  make  an  affidavit  or  to  take  sides  in  the  dispute,  but  he 
wrote  a  letter  from  which  the  following  is  extracted :  "  I 
cannot  have  the  least  difficulty  in  expressing  my  opinion 
that  you  have  made  a  great  advance  in  the  application  of 
my  method  of  correcting  the  compass  in  iron  ships,  by  your 
introduction  of  the  use  of  short  needles  for  the  compass- 
cards.  In  my  original  investigations,  when  the  whole  sub- 
ject was  in  darkness,  I  could  only  use  existing  means  for 
experiment,  namely  the  long-needle  compasses  then  ex- 
isting. But  when  I  applied  mechanical  theory  to  explana- 
tion of  the  results,  I  felt  grievously  the  deficiency  of  a  theory 
and  the  construction  which  it  suggested  (necessarily  founded 
on  assumption  that  the  proportion  of  the  needle-length  to 
the  other  elements  of  measure  is  small)  when  the  length  of 
the  needles  was  really  so  great.  I  should  possibly  have  used 
some  construction  like  yours,  but  the  Government  had  not 
then  a  single  iron  vessel,  and  did  not  seem  disposed  to  urge 
the  enquiry.  You,  under  happier  auspices,  have  successfully 
carried  it  out,  and,  I  fully  believe,  with  much  advantage  to 
the  science." — He  wrote  a  Paper  for  the  Athenaeum  and  had 
various  correspondence  on  the  subject  of  the  Badbury  Rings 
in  Dorsetshire,  which  he  (and  others)  considered  as  identical 
with  the  "  Mons  Badonicus  "  of  Gildas,  the  site  of  an  ancient 
British  battle. — In  February  he  was  in  correspondence  with 


360  GEORGE   BIDDELL  AIRY. 

the  Astronomer  Royal  on  Uniform  Time  Reckoning,  and  on 
considerations  relating  to  it. — On  June  6th  he  attended  the 
Annual  Visitation  of  the  Observatory,  and  brought  before 
the  Board  his  investigations: "of  the  Diurnal  Magnetic  In- 
equalities, and  the  revises  of  his  Lunar  Theory. 


1886 

From  June  8th  to  July  i/th  he  was  at  Play  ford. — And 
again  at  Playford  from  Oct.  5th  to  Nov.  8th. — On  March 
2/th  he  had  an  attack  of  gout  in  his  right  foot,  which  con- 
tinued through  April  and  into  May,  causing  him  much  incon- 
venience.— He  was  busy  with  the  Numerical  Lunar  Theory 
up  to  Sept.. 2 5th,  when  he  was  reading  the  last  proof-sheet 
received  from  the  printers:  during  this  period  his  powers 
were  evidently  failing,  and  there  are  frequent  references  to 
errors  discovered  and  corrected,  and  to  uncertainties  con- 
nected with  points  of  the  Theory.  But  his  great  work  on 
the  Numerical  Lunar  Theory  was  printed  in  this  year : 
and  there  can  be  no  doubt  that  he  experienced  a  great 
feeling  of  relief  when  this  was  accomplished. — He  was  in 
correspondence  with  Prof.  Adams  as  to  the  effect  of  his 
reduction  of  the  Coefficient  of  Lunar  Acceleration  on  the 
calculation  of  the  ancient  historical  eclipses. — He  compiled 
a  Paper  "On  the  establishment  of  the  Roman  dominion  in 
England,"  which  was  printed  in  1887. — He  wrote  a  notice  con- 
cerning events  in  the  life  of  Mr  John  Jackson  of  Rosthwaite 
near  Keswick,  a  well-known  guide  and  much-respected  au- 
thority on  matters  relating  to  the  Lake  District. — He  also 
wrote  a  short  account  of  the  connection  of  the  history  of 
Mdlle  de  Queroualle  with  that  of  the  Royal  Observatory 
at  Greenwich. — On  June  4th  he  attended  at  the  Annual 
Visitation  of  the  Observatory. 


AT  THE   WHITE   HOUSE,  GREENWICH.  361 


1887 

On  May  gth  to  nth  he  made  a  short  visit  to  Eastbourne 
and  the  neighbourhood. — From  June  8th  to  July  I3th  he  was 
at  Play  ford. — From  Aug.  29th  to  Sept.  5th  he  was  travelling 
in  Dorsetshire  and  Wiltshire :  he  went  first  to  Weymouth,  a 
very  favourite  centre  for  excursions  with  him,  and  afterwards 
visited  Bridport  and  Lyme  Regis :  then  by  Dorchester  to 
Blandford,  and  visited  the  Hod  Hill,  Badbury  Rings,  &c. : 
at  Wimborne  he  was  much  interested  in  the  architecture  of 
the  church :  lastly  he  visited  Salisbury,  Old  Sarum,  Stone- 
henge,  &c.,  and  returned  to  Greenwich. — From  Oct.  nth  to 
Nov.  1 2th  he  was  at  Playford. — During  this  year  he  partly 
occupied  himself  with  arranging  his  papers  and  drawings,  and 
with  miscellaneous  reading.  But  he  could  not  withdraw  his 
thoughts  from  his  Lunar  Theory,  and  he  still  continued  to 
struggle  with  the  difficulties  of  the  subject,  and  was  con- 
stantly scheming  improvements.  His  private  accounts  also 
now  gave  him  much  trouble.  Throughout  his  life  he  had 
been  accustomed  to  keep  his  accounts  by  double  entry  in 
very  perfect  order.  But  he  now  began  to  make  mistakes  and 
to  grow  confused,  and  this  distressed  him  greatly.  It  never 
seemed  to  occur  to  him  to  abandon  his  elaborate  system  of 
accounts,  and  to  content  himself  with  simple  entries  of 
receipts  and  expenses.  This  would  have  been  utterly  op- 
posed to  his  sense  of  order,  which  was  now  more  than  ever 
the  ruling  principle  of  his  mind.  And  so  he  struggled  with 
his  accounts  as  he  did  with  his  Lunar  Theory  till  his  powers 
absolutely  failed.  In  his  Journal  for  this  year  there  are 
various  entries  of  mental  attacks  of  short  duration  and  other 
ailments  ascribable  to  his  advanced  age. 

The  last  printed  "Papers  by  G.  B.  Airy"  belong  to  this 
year.  One  was  the  Paper  before  referred  to  "  On  the  estab- 
lishment of  the  Roman  dominion  in  England":  another  was 
on  the  solution  of  a  certain  Equation :  and  there  were  early 
reminiscences  of  the  Cambridge  Tripos,  &c. — In  February  he 


362  GEORGE   BIDDELL  AIRY. 

attended  a  little  to  a  new  edition  of  his  Ipswich  Lectures, 
but  soon  handed  it  over  to  Mr  H.  H.  Turner  of  the  Royal 
Observatory. — On  May  23rd  he  was  drawing  up  suggestions 
for  the  arrangement  of  the  S^ckford  School,  &c.,  at  Wood- 
bridge. — On  June  4th  he  attended  the  Visitation  of  the  Royal 
Observatory,  when  a  resolution  was  passed  in  favour  of 
complete  photography  of  the  star-sky. 

1888 

From  the  I4th  to  i6th  of  May  he  made  a  short  expedi- 
tion to  Bournemouth,  and  stopped  on  the  way  home  to  visit 
Winchester  Cathedral. — From  June  27th  to  Aug.  3rd  he  was 
at  Playford  ;  and  again  from  Oct.  I3th  to  Nov.  loth. — During 
the  first  half  of  the  year  he  continued  his  examination  of  his 
Lunar  Theory,  but  gradually  dropped  it.  There  are  several 
references  in  his  Journal  to  his  feelings  of  pain  and  weakness, 
both  mental  and  bodily :  at  the  end  of  March  he  had  an 
attack  of  gout  in  the  fingers  of  his  right  hand.  During  the 
latter  part  of  the  year  he  was  troubled  with  his  private  ac- 
counts, as  before. — He  does  not  appear  to  have  been  engaged 
on  any  miscellaneous  matters  calling  for  special  notice  in  this 
year.  But  he  kept  up  his  astronomical  correspondence — 
with  Lockyer  on  the  meteorite  system  of  planetary  formation  ; 
with  Pritchard  on  the  work  of  the  Oxford  University  Obser- 
vatory ;  with  Adams  on  his  Numerical  Lunar  Theory,  &c., 
and  with  others. — On  June  2nd  he  attended  the  Visitation  of 
the  Royal  Observatory. — He  amused  himself  occasionally 
with  reading  his  favourite  subjects  of  history  and  antiquities, 
and  with  looking  over  some  of  his  early  investigations  of 
scientific  questions. 

1889 

On  June  5th  he  made  a  one-day's  excursion  to  Colchester. 
— From  July  2nd  to  2/th  he  was  in  the  Cumberland  Lake 
District,  chiefly  at  Portinscale  near  Keswick.  While  staying 


AT   THE   WHITE   HOUSE,  GREENWICH.  363 

at  Portinscale  he  was  seized  with  a  sudden  giddiness  and  fell 
upon  the  floor:  he  afterwards  wrote  a  curious  account  of  the 
visions  which  oppressed  his  brain  immediately  after  the 
accident  He  returned  by  Solihull,  where  his  son  Osmund 
was  residing. — From  Oct.  4th  to  Nov.  8th  he  was  at  Playford. 
While  there  he  drew  up  a  short  statement  of  his  general  state 
of  health,  adverting  particularly  to  the  loss  of  strength  in  his 
legs  and  failure  of  his  walking  powers. — His  health  seems  to 
have  failed  a  good  deal  in  this  year :  on  Feb.  4th  he  had  an 
accidental  fall,  and  there  are  several  entries  in  his  Journal  of 
mental  attacks,  pains  in  his  limbs,  affection  of  his  eye-sight, 
&c. — In  the  early  part  of  the  year  he  was  much  engaged  on 
the  history  of  the  Airy  family,  particularly  on  that  of  his 
father. — In  this  year  the  White  House  was  sold  by  auction 
by  its  owners,  and  Airy  purchased  it  on  May  24th. — He  was 
still  in  difficulties  with  his  private  accounts,  but  was  making 
efforts  to  abandon  his  old  and  elaborate  system. —  For  his 
amusement  he  was  chiefly  engaged  on  Theological  Notes 
which  he  was  compiling:  and  also  on  early  optical  investi- 
gations, &c. 

On  June  1st  he  attended  the  Visitation  of  the  Royal 
Observatory,  and  moved  a  resolution  that  a  Committee  be 
appointed  to  consider  whether  any  reduction  can  be  effected 
in  the  amount  of  matter  printed  in  the  Volume  of  Observa- 
tions of  the  Royal  Observatory.  During  his  tenure  of  office 
he  had  on  various  occasions  brought  this  subject  before  the 
Board  of  Visitors,  and  with  his  usual  tenacity  of  purpose  he 
now  as  Visitor  pressed  it  upon  their  notice. — In  May  he 
zealously  joined  with  others  in  an  application  to  get  for 
Dr  Huggins  a  pension  on  the  Civil  List. — In  January  he 
prepared  a  short  Paper  illustrated  with  diagrams  to  exhibit 
the  Interference  of  Solar  Light,  as  used  by  him  in  his 
Lectures  at  Cambridge  in  1836:  but  it  does  not  appear  to 
have  been  published. — In  April  he  received  a  copy  of  a 
Paper  by  Mr  Rundell,  referring  to  the  complete  adoption  of 
his  system  of  compass  correction  in  iron  ships,  not  only  in 


364  GEORGE   BIDDELL  AIRY. 

the  merchant  service,  but  also  in  the  Navy.  This  was  a 
matter  of  peculiar  gratification  to  Airy,  who  had  always 
maintained  that  the  method  of  Tables  of  Errors,  which  had 
been  so  persistently  adhered  ;to  by  the  Admiralty,  was  a 
mistake,  and  that  sooner  or  later  they  would  find  it  necessary 
to  adopt  his  method  of  mechanical  correction.  The  passage 
referred  to  is  as  follows :  "  The  name  of  Sir  George  Airy, 
the  father  of  the  mechanical  compensation  of  the  compass  in 
iron  vessels,  having  just  been  mentioned,  it  may  not  be  inap- 
propriate to  remind  you  that  the  present  year  is  the  fiftieth 
since  Sir  George  Airy  presented  to  the  Royal  Society  his 
celebrated  paper  on  this  subject  with  the  account  of  his  ex- 
periments on  the  '  Rainbow '  and  '  Ironsides.'  Fifty  years  is 
a  long  period  in  one  man's  history,  and  Sir  George  Airy  may 
well  be  proud  in  looking  back  over  this  period  to  see  how 
complete  has  been  the  success  of  his  compass  investigation. 
His  mode  of  compensation  has  been  adopted  by  all  the 
civilized  world.  Sir  William  Thomson,  one  of  the  latest  and 
perhaps  the  most  successful  of  modern  compass  adjusters, 
when  he  exhibited  his  apparatus  in  1878  before  a  dis- 
tinguished meeting  in  London,  remarked  that  within  the 
last  ten  years  the  application  of  Sir  George  Airy's  method 
had  become  universal,  not  only  in  the  merchant  service,  but 
in  the  navies  of  this  and  other  countries,  and  added — The 
compass  and  the  binnacles  before  you  are  designed  to 
thoroughly  carry  out  in  practical  navigation  the  Astronomer 
Royal's  principles." 


1890 

From  May  i/th  to  24th  he  was  on  an  expedition  to 
North  Wales,  stopping  at  Chester,  Conway,  Carnarvon,  Bar- 
mouth,  and  Shrewsbury. — From  June  i8th  to  July  24th  he 
was  at  Playford  ;  and  again  from  Oct.  nth  to  Nov.  I5th. — 
In  this  year  his  powers  greatly  failed,  and  he  complained 
frequently  of  mental  attacks,  weakness  of  limbs,  lassitude,  and 


AT  THE   WHITE   HOUSE,   GREENWICH.  365 

failure  of  sleep.  He  occupied  himself  as  usual  with  his  books, 
papers,  and  accounts  ;  and  read  Travels,  Biblical  History,  &c., 
but  nothing  very  persistently. 

On  June  7th  he  attended  the  Visitation  of  the  Royal 
Observatory. — From  a  letter  addressed  to  him  by  Mr  J. 
Hartnup,  of  Liverpool  Observatory,  it  appears  that  there  had 
grown  up  in  the  mercantile  world  an  impression  that  very 
accurate  chronometers  were  not  needed  for  steam  ships, 
because  they  were  rarely  running  many  days  out  of  sight  of 
land  :  and  Airy's  opinion  was  requested  on  this  matter.  He 
replied  as  follows  on  Mar.  3rd  :  "  The  question  proposed  in 
your  letter  is  purely  a  practical  one.  (i)  If  a  ship  is  likely 
ever  to  be  two  days  out  of  sight  of  land,  I  think  that  she 
ought  to  be  furnished  with  two  good  chronometers,  properly 
tested.  (2)  For  the  proper  testing  of  the  rates  of  the  chrono- 
meters, a  rating  of  the  chronometers  for  three  or  four  days  in 
a  meridional  observatory  is  necessary.  A  longer  testing  is 
desirable." — In  March  he  was  in  correspondence,  as  one  of 
the  Trustees  of  the  Sheepshanks  Fund,  with  the  Master  of 
Trinity  relative  to  grants  from  the  Fund  for  Cambridge 
Observatory. 


1891 

From  June  i6th  to  July  I5th  he  was  at  Playford.  And 
again  from  Oct.  I2th  to  Dec.  2nd  (his  last  visit).  Throughout 
the  year  his  weakness,  both  of  brain  power  and  muscular 
power,  had  been  gradually  increasing,  and  during  this  stay  at 
Playford,  on  Nov.  i  ith,  he  fell  down  in  his  bed-room  (probably 
from  failure  of  nerve  action)  and  was  much  prostrated  by  the 
shock.  For  several  days  he  remained  in  a  semi-unconscious 
condition,  and  although  he  rallied,  yet  he  continued  very 
weak,  and  it  was  not  until  Dec.  2nd  that  he  could  be  removed 
to  the  White  House.  Up  to  the  time  of  his  fall  he  had  been 
able  to  take  frequent  drives  and  even  short  walks  in  the 


366  GEORGE   BIDDELL  AIRY. 

neighbourhood  that  he  was  so  fond  of,  but  he  could  take  but 
little  exercise  afterwards,  and  on  or  about  Nov.  iSth  he  made 
the  following  note  :  "  The  saddest  expedition  that  I  have  ever 
made.  We  have  not  left  home  for  several  days." 

The  rapid  failure  of  his  powers  during  this  year  is  well 
exemplified  by  his  handwriting  in  his  Journal  entries,  which, 
with  occasional  rallies,  becomes  broken  and  in  places  almost 
illegible.  He  makes  frequent  reference  to  his  decline  in 
strength  and  brain-power,  and  to  his  failing  memory,  but  he 
continued  his  ordinary  occupations,  made  frequent  drives 
around  Blackheath,  and  amused  himself  with  his  family  history 
researches,  arrangement  of  papers,  and  miscellaneous  reading  : 
and  he  persisted  to  the  last  with  his  private  accounts.  His 
interest  in  matters  around  him  was  still  keen.  On  June  I3th 
he  was  driving  along  the  Greenwich  Marshes  in  order  to 
track  the  course  of  the  great  sewer;  and  on  August  5th  he 
visited  the  Crossness  Sewage  Works  and  took  great  interest 
in  the  details  of  the  treatment  of  the  sewage. — In  March  he 
contributed,  with  great  satisfaction,  to  the  Fund  for  the 
Portrait  of  his  old  friend  Sir  G.  G.  Stokes,  with  whom  he  had 
had  so  much  scientific  correspondence. — On  July  25th  an  after- 
noon party  was  arranged  to  celebrate  the  poth  anniversary  of 
his  birthday  (the  actual  anniversary  was  on  July  27th). 
None  of  his  early  friends  were  there :  he  had  survived  them 
all.  But  invitations  were  sent  to  all  his  scientific  and  private 
friends  who  could  be  expected  to  come,  and  a  large  party 
assembled.  The  afternoon  was  very  fine,  and  he  sat  in  the 
garden  and  received  his  friends  (many  of  whom  had  come 
from  long  distances)  in  good  strength  and  spirits.  It  was  a 
most  successful  gathering  and  was  not  without  its  meaning ; 
for  it  was  felt  that,  under  the  circumstances  of  his  failing 
powers,  it  was  in  all  probability  a  final  leave-taking. — On 
July  27th  he  went  down  to  the  Greenwich  Parish  Church 
at  9  p.m.,  to  be  present  at  the  illumination  of  the  church 
clock  face  for  the  first  time — a  matter  of  local  interest 
which  had  necessitated  a  good  deal  of  time  and  money. 


AT   THE   WHITE   HOUSE,   GREENWICH.  367 

On  this  occasion  at  the  request  of  the  company  assembled 
in  and  around  the  Vestry  he  spoke  for  about  a  quarter 
of  an  hour  on  Time — the  value  of  accurate  time,  the  dis- 
semination of  Greenwich  time  throughout  the  country  by 
time-signals  from  the  Observatory,  and  the  exhibition  of  it 
by  time-balls,  &c.,  &c., — the  subject  to  which  so  large  a  part 
of  his  life  had  been  devoted.  It  was  a  pleasant  and  able 
speech  and  gave  great  satisfaction  to  the  parishioners, 
amongst  whom  he  had  lived  for  so  many  years. — He  received 
two  illuminated  addresses — one  from  the  Astronomer  Royal 
and  Staff  of  the  Royal  Observatory ;  the  other  from  the 
Vorstand  of  the  Astronomische  Gesellschaft  at  Berlin — and 
various  private  letters  of  congratulation.  The  address  from 
the  Staff  of  the  Observatory  was  worded  thus :  "  We,  the 
present  members  of  the  Staff  of  the  Royal  Observatory, 
Greenwich,  beg  to  offer  you  our  most  sincere  congratulations 
on  the  occasion  of  your  QOth  birthday.  We  cannot  but  feel 
how  closely  associated  we  are  with  you,  in  that  our  whole 
energies  are  directed  to  the  maintenance  and  development  of 
that  practical  astronomical  work,  of  which  you  essentially 
laid  the  foundation.  It  affords  us  great  pleasure  to  think 
that  after  the  conclusion  of  your  life's  work,  you  have  been 
spared  to  live  so  long  under  the  shadow  of  the  noble  Obser- 
vatory with  which  your  name  was  identified  for  half  a 
century,  and  with  which  it  must  ever  remain  associated." 

After  his  return  from  Playford  he  seemed  to  rally  a  little : 
but  he  soon  fell  ill  and  was  found  to  be  suffering  from  hernia. 
This  necessitated  a  surgical  operation,  which  was  successfully 
performed  on  Dec.  i/th.  This  gave  him  effectual  relief,  and 
after  recovering  from  the  immediate  effects  of  the  operation, 
he  lay  for  several  days  quietly  and  without  active  pain 
reciting  the  English  poetry  with  which  his  memory  was 
stored.  But  the  shock  was  too  great  for  his  enfeebled  con- 
dition, and  he  died  peacefully  in  the  presence  of  his  six 
surviving  children  on  Jan.  2nd,  1892.  He  was  buried  in 
Playford  churchyard  on  Jan.  /th.  The  funeral  procession 


368  GEORGE   BIDDELL  AIRY. 

was  attended  at  Greenwich  by  the  whole  staff  of  the  Royal 
Observatory,  and  by  other  friends,  and  at  his  burial  there 
were  present  two  former  Fellows  of  the  College  to  which 
he  had  been  so  deeply  attached. 


APPENDIX. 

LIST    OF    PRINTED    PAPERS    BY    G.    B.    AIRY. 
LIST   OF   BOOKS   WRITTEN    BY   G.   B.   AIRY. 


A.  B.  24 


PRINTED  PAPERS  BY  G.  B.  AIRY. 


WITH  the  instinct  of  order  which  formed  one  of  his  chief 
characteristics  Airy  carefully  preserved  a  copy  of  every  printed  Paper 
of  his  own  composition.  These  were  regularly  bound  in  large  quarto 
volumes,  and  they  are  in  themselves  a  striking  proof  of  his  wonderful 
diligence.  The  bound  volumes  are  14  in  number,  and  they  occupy 
a  space  of  2  ft.  6  in.  on  a  shelf.  They  contain  518  Papers,  a  list  of 
which  is  appended,  and  they  form  such  an  important  part  of  his  life's 
work,  that  his  biography  would  be  very  incomplete  without  a  refer- 
ence to  them. 

He  was  very  careful  in  selecting  the  channels  for  the  publication 
of  his  Papers.  Most  of  the  early  Papers  were  published  in  the 
Transactions  of  the  Cambridge  Philosophical  Society,  but  several  of 
the  most  important,  such  as  his  Paper  "  On  an  inequality  of  long 
period  in  the  motions  of  the  Earth  and  Venus,"  were  published  in 
the  Philosophical  Transactions  of  the  Royal  Society,  and  others, 
such  as  the  articles  on  "  The  Figure  of  the  Earth,"  "  Gravitation," 
"  Tides  and  Waves,"  &c.,  were  published  in  Encyclopaedias.  After 
his  removal  to  Greenwich  nearly  all  his  Papers  on  scientific  subjects 
(except  astronomy),  such  as  Tides,  Magnetism,  Correction  of  the 
Compass,  &c.,  &c.,  were  communicated  to  the  Royal  Society,  and 
were  published  in  the  Philosophical  Transactions.  But  everything 
astronomical  was  reserved  for  the  Royal  Astronomical  Society.  His 
connection  with  that  Society  was  very  close :  he  had  joined  it  in  its 
earliest  days  (the  date  of  his  election  was  May  gth,  1828),  and 
regarded  it  as  the  proper  medium  for  the  discussion  of  current 
astronomical  questions,  and  for  recording  astronomical  progress. 
He  was  unremitting  in  his  attendance  at  the  Monthly  Meetings  of 
the  Society,  and  was  several  times  President.  In  the  Memoirs  of 
the  Society  35  of  his  Papers  are  printed,  and  in  addition  129  Papers 
in  the  Monthly  Notices.  In  fact  a  meeting  of  the  Society  rarely 


PRINTED   PAPERS   BY  G.   B.   AIRY.  371 

passed  without  some  communication  from  him,  and  such  was  his 
wealth  of  matter  that  sometimes  he  would  communicate  as  many  as 
3  Papers  on  a  single  evening.  For  the  publication  of  several  short 
mathematical  Papers,  and  especially  for  correspondence  on  disputed 
points  of  mathematical  investigation,  he  chose  as  his  vehicle  the 
Philosophical  Magazine,  to  which  he  contributed  32  Papers. 
Investigations  of  a  more  popular  character  he  published  in  the 
Athenaeum,  which  he  also  used  as  a  vehicle  for  his  replies  to  attacks 
on  his  work,  or  on  the  Establishment  which  he  conducted :  in  all  he 
made  55  communications  to  that  Newspaper.  To  various  Societies, 
such  as  the  Institution  of  Civil  Engineers,  the  British  Association, 
the  Royal  Institution,  &c.,  he  presented  Papers  or  made  com- 
munications on  subjects  specially  suited  to  each  ;  and  in  like  manner 
to  various  Newspapers  :  there  were  58  Papers  in  this  category.  In 
so  long  an  official  life  there  would  naturally  be  a  great  number  of 
Official  Reports,  Parliamentary  Returns,  &c.,  and  these,  with  other 
miscellaneous  Papers  printed  for  particular  objects  and  for  a  limited 
circulation,  amounted  in  all  to  141.  Under  this  head  come  his 
Annual  Reports  to  the  Board  of  Visitors,  which  in  themselves  con- 
tain an  extremely  full  and  accurate  history  of  the  Observatory  during 
his  tenure  of  office.  There  are  46  of  these  Reports,  and  they  would 
of  themselves  form  a  large  volume  of  about  740  pages. 


24—2 


The  following  summary  of  his  Printed  Papers  shews  the  manner 
in  which  they  were  distributed  : 


SUMMARY  OF  PRINTED  PAPERS  BY  G.  B.  AIRY. 

Number  of 

Papers. 

In  the  Transactions  of  the  Cambridge  Philosophical  Society  30 

In  the  Philosophical  Transactions  of  the  Royal  Society .         .^ '  29 

In  the  Proceedings  of  the  Royal  Society        .        .         .        ,  9 

In  the  Memoirs  of  the  Royal  Astronomical  Society         .         .  35 

In  the  Monthly  Notices  of  the  Royal  Astronomical  Society    .  129 

In  the  Philosophical  Magazine  and  Journal  .         .         . ' '    ! .    "  32 

In  the  Athenaeum         .         .         .         .        .         .'        .         .  55 

In  Encyclopaedias,  and  in  various  Newspapers  and  Trans- 
actions     .         .         .         .         .         ...         .v  58 

In    Official    Reports,     Addresses,    Parliamentary    Returns, 
Evidence     before    Committees,     Lectures,     Letters, 

Sundry  Treatises,  and  Papers 141 

Total 518 


PRINTED    PAPERS    BY   G.   B.   AIRY. 


Date  when  read 
or  published.  Title  of  Paper.  Where  published. 

1822  Nov.  25  On  the  use  of  Silvered  Glass  for  the  Mirrors     Camb.  Phil.  Soc. 

of  Reflecting  Telescopes. 
1824  Mar.  15  On  the  Figure  assumed  by  a  Fluid  Homo-  Camb.  Phil.  Soc. 

geneous  Mass,  whose  Particles  are  acted 

on  by  their  mutual  Attraction,  and  by 

small  extraneous  Forces. 
1824  May  17  On  the  Principles  and  Construction  of  the  Camb.  Phil.  Soc. 

Achromatic   Eye-Pieces  of   Telescopes, 

and  on  the  Achromatism  of  Microscopes. 

1824  Trigonometry.  Encycl.  Metrop. 

1825  Feb.  21    On  a  peculiar  Defect  in  the  Eye,  and  a     Camb.  Phil.  Soc. 

mode  of  correcting  it. 

1825  May  2     On  the  Forms  of  the  Teeth  of  Wheels.  Camb.  Phil.  Soc. 

1826  May  8     On  Laplace's  Investigation  of  the  Attraction     Camb.  Phil.  Soc. 

of  Spheroids  differing  little  from  a  Sphere. 
1826  June  15    On  the  Figure  of  the  Earth.  Phil.  Trans. 

1826  Nov.  26  On  the  Disturbances  of  Pendulums  and     Camb.  Phil.  Soc. 

Balances,  and  on  the  Theory  of  Escape- 
ments. 

1827  Feb.  15   Remarks   on   a   Correction   of   the   Solar     Phil.  Trans. 

Tables,,  required  by  Mr  South's  observa- 
tions. 

1827  May  9     On  some  Passages  in  Mr  Ivory's  Remarks     Phil.  Mag. 
on  a  Memoir  by  M.  Poisson  relating  to 
the  Attraction  of  Spheroids. 
May  14   On  the  Spherical  Aberration  of  the  Eye-     Camb.  Phil.  Soc. 

pieces  of  Telescopes. 

On  the  corrections   in    the    elements    of    Phil.  Trans. 
Delambre's  Solar  Tables  required  by  the 
observations  made  at  the  Royal  Observa- 
tory, Greenwich. 


l827JMay  21 
1827  Dec.  6 


374 


APPENDIX. 


Date  when  read 
or  published. 


Title  of  Paper. 


1828  Feb.  26  Address  to  the  Members  of  the  Senate,  on 
an  Improvement  in  the  Position  of  the 
Plumian  Professor.  '. 

1828  Nov.  24  On  the  Longitude  of  the  Cambridge  Ob- 

servatory. 

1829  Nov.  13  On  a  method  of  determining  the  Mass  of 

the  Moon  from  Transit  Observations  of 
Venus  near  her  inferior  conjunction. 
1829  Nov.  16  On  a  Correction  requisite  to  be  applied  to 
the  Length  of  a  Pendulum  consisting  of 
a  Ball  suspended  by  a  fine  Wire. 

1829  Dec.  14  On    certain    Conditions    under    which    a 

Perpetual  Motion  is  possible. 

1830  Aug.  17  Figure  of  the  Earth. 

1831  Feb.  21    On  the  Nature  of  the  Light  in  the  Two 

Rays  produced  by  the  Double  Refraction 

of  Quartz. 

1831  Apr.  1 8   Addition  to  the  above  Paper. 
1831  Nov.  14  On  a  remarkable  Modification  of  Newton's 

Rings. 

1831  Nov.  24  On  an  inequality  of  long  period   in   the 

motions  of  the  Earth  and  Venus. 

1832  Jan.  2      Translation    of  Encke's   Dissertation   (on 

Encke's  Comet)  contained  in  Nos.  210 
and  2H  of  the  Astronomische  Nach- 
richten. 

1832  Mar.  5  On  a  new  Analyzer,  and  its  use  in  Experi- 
ments of  Polarization. 

1832  Mar.  19  On  the  Phenomena  of  Newton's  Rings 
when  formed  between  two  transparent 
Substances  of  different  refractive  Powers. 

1832  May  2  Report  on  the  Progress  of  Astronomy 
during  the  present  century. 

1832  Oct.         Report  of  the  Syndicate  of  the  Cambridge 

Observatory. 

1833  Feb.  2     Remarks  on  Mr  Potter's  Experiment  on 

Interference. 

1833  Apr.  12  On  the  Mass  of  Jupiter,  as  determined 
from  the  Observation  of  Elongations  of 
the  Fourth  Satellite. 

1833  Syllabus  of  a  Course  of  Experimental 

Lectures. 

1833  May  7  On  the  Calculation  of  Newton's  Experi- 
ments on  Diffraction. 


Where  published. 


Camb.  Phil.  Soc. 

Astr.  Soc. 
(Memoirs.) 

Camb.  Phil.  Soc. 


Camb.  Phil.  Soc. 

Encycl.  Metrop. 
Camb.  Phil.  Soc. 


Camb.  Phil.  Soc. 
Camb.  Phil.  Soc. 

Phil.  Trans. 


Camb.  Phil.  Soc. 
Camb.  Phil.  Soc. 

Trans.  Brit.  Ass. 

Phil.  Mag. 

R.  Astr.  Soc. 
(Memoirs.) 

Camb.  Phil.  Soc. 


PRINTED   PAPERS    BY   G.    B.   AIRY. 


375 


Date  when  read 
or  published.  Title  of  Paper. 

1833  May  7  Remarks  on  Sir  David  Brewster's  Paper 
"On  the  Absorption  of  Specific  Rays" 
&c. 

1833  May  1 6  Results  of  the  Repetition  of  Mr  Potter's 
Experiment  of  interposing  a  Prism  in 
the  Path  of  Interfering  Light. 

1833  May  On  a  supposed  black  bar  formed  by  Dif- 
fraction. 

1833  June  20  Report  on  Mr  Barlow's  Fluid- Lens  Tele- 

scope. 

1834  Mar.  14  Continuation  of  Researches  into  the  Value 

of  the  Mass  of  Jupiter,  by  observation  of 
the  Elongations  of  the  Fourth  Satellite. 

1834  Apr.  14  On  the  Latitude  of  Cambridge  Obser- 
vatory. 

1834  June  Report  of  the  Syndicate  of  the  Cambridge 
Observatory. 

1834  June  13  On  the  Position  of  the  Ecliptic,  as  inferred 
from  Transit  and  Circle  Observations 
made  at  Cambridge  Observatory  in  the 
year  1833. 

1834  June  13  Observations  of  the  Solar  Eclipse  of  July 
1 6th,  1833,  made  at  Cambridge  Observa- 
tory, and  Calculations  of  the  Observa- 
tions. 

1834  Nov.  24  On  the  Diffraction  of  an  Object-Glass  with 
Circular  Aperture. 

1834  Dec.  3     On  the   Calculation  of  the  Perturbations 

of  the  Small  Planets  and  the  Comets  of 
short  period. 

1835  May  8     Continuation  of  Researches  into  the  Value 

of  Jupiter's  Mass. 
1835  June        Report  of  the  Syndicate  of  the  Cambridge 

Observatory. 
1835  June  12  On  the  Position  of  the  Ecliptic,  as  inferred 

from  Observations  with  the  Cambridge 

Transit  and  Mural  Circle,  made  in  the 

year  1834. 
1835  June  12  On  the  Time  of  Rotation  of  Jupiter. 


1836  Feb.  12  Speech  on  delivering  the  Medal  of  the 
R.  Astr.  Soc.  to  Sir  John  Herschel. 

1836  June  4  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 


Where  published. 
Phil.  Mag. 

Phil.  Mag. 

Phil.  Mag. 

R.  Soc.  (Proc.) 

R.  Astr.  Soc. 
(Memoirs.) 

Camb.  Phil.  Soc. 


R.  Astr.  Soc. 
(Memoirs.) 


R.  Astr.  Soc. 
(Memoirs.) 


Camb.  Phil.  Soc. 

Naut.  Aim. 
(1837,  App.) 

R.  Astr.  Soc. 
(Memoirs.) 


R.  Astr.  Soc. 
(Memoirs.) 


R.  Astr.  Soc. 

(Memoirs.) 
R.  Astr.  Soc. 

(Proc.) 


376 


APPENDIX. 


Date  when  read 
or  published. 


Title  of  Paper. 


Where  published. 


1836  June  9     Report   upon   a   Letter  (on   a    Systematic     R.  Soc.     (Proc.) 

Course  of  Magnetic  Observations)  ad- 
dressed by  M.  le  Baron  de  Humboldt  to 
His  Royal  Highness  the  President  of 
the  Royal  Society  (by  S.  Hunter  Christie 
and  G.  B.  Airy).  i. 

!$37  Jan.  13    Continuation  of  Researches  into  the  Value     R.  Astr.  Soc. 
of  Jupiter's  Mass.  (Memoirs.) 

1837  Feb.  10   Speech   on   delivering  the   Medal   of   the     R.  Astr.  Soc. 


R.  Astr.  Soc.  to  Professor  Rosenberger. 
1837  Mar.  10  Results  of  the  Observations  of  the   Sun, 
Moon,  and  Planets,  made  at  Cambridge 
Observatory  in  the  years  1833,  1834,  and 


1837  May  12  On  the  Position  of  the  Ecliptic,  as  inferred 
from  Observations  with  the  Cambridge 
Transit  and  Mural  Circle,  made  in  the 
year  1835. 

1837  June  3  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1837  Sept.  9  Address  delivered  in  the  Town  Hall  of 
Neath. 

1837  Nov.  10  On  the  Parallax  of  a  Lyrae. 


(Proc.) 

R.  Astr.  Soc. 
(Memoirs.) 


R.  Astr.  Soc. 
(Memoirs.) 


R.  Astr.  Soc. 
(Memoirs.) 


1838  Feb.  10  Address    to    the    Earl    of    Burlington    on 

Religious  Examination  in  the  University 

of  London. 
1838  Mar.  26  On  the  Intensity  of  Light  in  the  neighbour-     Camb.  Phil.  Soc. 

hood  of  a  Caustic. 
1838  June  2     Report  of  the  Astronomer  Royal  to  the 

Board  of  Visitors. 

1838  Dec.  14  A  Catalogue  of  726  Stars,  deduced  from     R.  Astr.  Soc. 

the  Observations  made  at  the  Cambridge        (Memoirs.) 
Observatory,  from  1828  to  1835  ;  reduced 
to  January  I,  1830. 

1839  Apr.  25   Account    of    Experiments    on    Iron-built     Phil.  Trans. 

Ships,  instituted  for  the  purpose  of  dis- 
covering a  correction  for  the  deviation 
of  the  Compass  produced  by  the  iron  of 
the  Ships. 

1839  June  i     Report   of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1839  Nov.  8     On  the   Determination   of   the   Orbits   of    R.  Astr.  Soc. 
Comets,  from  Observations.  (Memoirs.) 


PRINTED   PAPERS   BY   G.    B.   AIRY. 


377 


Date  when  read 
or  published.  Title  of  Paper. 

1839  Article  "  Gravitation." 

1839  Article  "Greenwich  Observatory." 

1840  Mar.  2     On  a  New  Construction  of  the  Going-Fusee. 
1840  Mar.  13  On  the  Regulator  of  the  Clock-work  for 

effecting  uniform  Movement  of  Equa- 
toreals. 

1840  May  15  On  the  Correction  of  the  Compass  in  Iron- 
built  Ships. 

1840  Results  of  Experiments  on  the  Disturbance 

of  the  Compass  in  Iron-built  Ships. 

1840  June  6  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1840  June  1 8  On  the  Theoretical  Explanation  of  an  ap- 
parent new  Polarity  in  Light. 

1840  Nov.  19  Supplement  to  the  above  Paper. 

1840  Dec.  4     On  the  Diffraction  of  an  Annular  Aperture. 

1840  Dec.  9     Remarks   on    Professor    Challis's    Investi- 

gation of  the  Motion  of  a  Small  Sphere 
vibrating  in  a  Resisting  Medium. 

1841  Jan.  20    Correction  to  the   above   Paper  "On  the 

Diffraction,"  £c. 

1841  Mar.  22  Remarks  on  Professor  Challis's  Reply  to 
Mr  Airy's  Objections  to  the  Investi- 
gation of  the  Resistance  of  the  Atmo- 
sphere to  an  Oscillating  Sphere. 

1841  June  5  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1841  July  10  Reply  to  Professor  Chain's,  on  the  Investi- 
gation of  the  Resistance  of  the  Air  to  an 
Oscillating  Sphere. 

1841  Oct.  26    Extraordinary  Disturbance  of  the  Magnets. 

1841  Nov.  25  On  the  Laws  of  the  Rise  and  Fall  of  the 
Tide  in  the  River  Thames. 

1841  Dec.  21   Report  of  the  Commissioners  appointed  to 

consider  the  steps  to  be  taken  for  Res- 
toration of  the  Standards  of  Weight  and 
Measure. 

1842  Apr.  16   On  the  IKTIS  of  Diodorus. 

1842  May  13   Account  of  the  Ordnance  Zenith  Sector. 


Where  published. 

Penny  Cyclop. 
Penny  Cyclop. 
Camb.  Phil.  Soc. 
R.  Astr.  Soc. 


Un.  Serv.  Journ. 

(Proc.) 
J.  Weale. 


Phil.  Trans. 

Phil.  Trans. 
Phil.  Mag. 
Phil.  Mag. 


Phil.  Mag. 
Phil.  Mag. 


Phil.  Mag. 


Phil.  Trans. 


1842  June  4     Report   of  the  Astronomer  Royal  to  the 

Board  of  Visitors. 
1842  Nov.  ii  Observations  of  the  Total  Solar  Eclipse  of 

1842  July  7. 


Athenaeum. 
R.  Astr.  Soc. 
(Proc.) 


R.  Astr.  Soc. 
(Memoirs.) 


378 


APPENDIX. 


Date  when  read 
or  published. 


Title  of  Paper. 


1842  Dec.  i  Remarks  on  the  Present  State  of  HatclifFs 
Charity  (Greenwich).. 

1842  Article  on  Tides  and  Waves. 

1843  Mar.  2     On  the  Laws  of  Individual  Tides  at  South- 

ampton and  at  Ipswich. 

1843  Apr.  29   On  Monetary  and  Metrical  Systems,     i. 

1843  June  3  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1843  Sept.  25  Address  to  the  Individual  Members  of  the 
Board  of  Visitors  of  the  Royal  Observa- 
tory (proposing  the  Altazimuth). 

1843  Oct.  6  Account  of  the  Northumberland  Equatoreal 
and  Dome,  attached  to  the  Cambridge 
Observatory. 

1843  Nov.  10  Address  and  Explanation  of  the  proposed 

Altitude  and  Azimuth  Instrument  to  the 
Board  of  Visitors  of  the  Royal  Observa- 
tory. 

1844  June  i     Report  of  the  Astronomer  Royal  to   the 

Board  of  Visitors. 

1844  Dec.  12  On  the  Laws  of  the  Tides  on  the  Coasts  of 

Ireland,  as  inferred  from  an  extensive 
series  of  observations  made  in  connec- 
tion with  the  Ordnance  Survey  of  Ireland. 

1845  Jan-  Io  On  the   Flexure   of  a  Uniform  Bar  sup- 

ported by  a  number  of  equal  Pressures 

applied  at  equidistant  points,  &c. 
1845  Feb.  14   Speech  on  delivering  the   Medal  of  the 

R.  Astr.  Soc.  to  Capt.  Smyth. 
1845  May  9     On  a  New  Construction  of  the   Divided 

Eye-Glass  Double-Image  Micrometer. 
1845  June  7     Report  of  the  Astronomer  Royal  to   the 

Board  of  Visitors. 

1845  July  21    On  Wexford  Harbour. 

1846  Report  of  the  Gauge  Commissioners.    And 

letter  to  Sir  E.  Ryan. 

1846  May  7  On  the  Equations  applying  to  Light  under 
the  action  of  Magnetism. 

1846  May  12  Remarks  on  Dr  Faraday's  Paper  on  Ray- 
vibrations. 

1846  May  25  On  a  Change  in  the  State  of  an  Eye 
affected  with  a  Mai-formation. 

1846  June  6  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 


"Where  published. 
Private. 

Encyc.  Metrop. 
Phil.  Trans. 


Athenseum. 


Phil.  Trans. 


R.  Astr.  Soc. 
(Memoirs.) 

R.  Astr.  Soc. 

(Proc.) 
R.  Astr.  Soc. 

(Memoirs.) 


Phil.  Mag. 
Phil.  Mag. 
Camb.  Phil.  Soc. 


PRINTED   PAPERS   BY   G.    B.   AIRY. 


379 


Date  when  read 
or  published. 


Title  of  Paper. 


1846  June  Account  of  the  Measurement  of  an  Arc  of 
Longitude  between  the  Royal  Observa- 
tory of  Greenwich  and  the  Trigonometri- 
cal Station  of  Feagh  Main,  in  the  Island 
of  Valentia. 

1846  July  25  Letter  to  Sir  Robert  Harry  Inglis,  Bart., 
M.P.,  in  answer  to  Sir  James  South's 
attack  on  the  Observations  at  the  Green- 
wich Observatory. 

1846  Nov.  On  the  Bands  formed  by  the  partial  Inter- 
ception of  the  Prismatic  Spectrum. 

1846  Nov.  13  Account  of  some  circumstances  historically 

connected  with  the  Discovery  of  the 
Planet  exterior  to  Uranus. 

1847  Jan.  8      Reduction  of  the  Observations  of  H alley's 

Comet  made  at  the  Cambridge  Obser- 
vatory in  the  years  1835  and  1836. 

1847  Jan.  8  On  a  proposed  Alteration  of  Bessel's  Me- 
thod for  the  Computation  of  the  Correc- 
tions by  which  the  Apparent  Places  of 
Stars  are  derived  from  the  Mean  Places. 

1847  Feb.  On  Sir  David  Brewster's  New  Analysis  of 
Solar  Light. 

1847  Feb.  20   On  the  Name  of  the  New  Planet. 

1847  Feb.  27    Mr  Adams  and  the  New  Planet. 

1847  Plan  of  the  Buildings  and  Grounds  of  the 

Royal  Observatory,  Greenwich,  with  Ex- 
planation and  History. 

1847  May  14  Explanation  of  Hansen's  Perturbations  of 
the  Moon  by  Venus. 

1847  June  5  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1847  Nov.  30  Address  to  the  Individual  Members  of  the 
Board  of  Visitors  of  the  Royal  Observa- 
tory. (Zenith  Tube.) 

1847  Dec.  10   Results  deduced  from  the  Occultations  of 

Stars  and  Planets  by  the  Moon,  ob- 
served at  Cambridge  Observatory  from 
1830  to  1835. 

1848  Feb.  ii  Abstract  of  Struve's  "  Etudes  d'Astronomie 

Stellaire." 

1848  Mar.  13  Syllabus  of  Lectures  on  Astronomy  to  be 
delivered  at  the  Temperance  Hall, 
Ipswich. 


Where  published. 

R.  Astr.  Soc. 
(Month.  Not.) 


Athenaeum. 


Phil.  Mag. 

R.  Astr.  Soc. 
(Memoirs.) 

R.  Astr.  Soc. 
(Memoirs.) 

R.  Astr.  Soc. 
(Memoirs.) 


Phil.  Mag. 

Athenaeum. 
Athenaeum. 


R.  Astr.  Soc. 
(Month.  Not.) 


R.  Astr.  Soc. 
(Memoirs.) 


R.  Astr.  Soc. 

(Month.  Not.) 


380 


APPENDIX. 


Date  when  read 
or  published. 


Title  of  Paper. 


1848  Apr.  10  Remarks  on  Prof.  Challis's  Theoretical 
Determination  of  the  Velocity  of  Sound. 

1848  May  8  Supplement  to  a  Paper  on  the  Intensity  of 
Light  in  the  neighbourhood  of  a  Caustic. 

1848  May  12  Address  to  Individual  Members  of  the 
Board  of  Visitors.  (New  Transit  Circle, 
Reflex  Zenith  Tube,  £c.) 

1848  June  3  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1848  June  9  Corrections  of  the  Elements  of  the  Moon's 
Orbit,  deduced  from  the  Lunar  Observa- 
tions made  at  the  Royal  Observatory  of 
Greenwich  from  1750  to  1830. 

1848  Aug.  9  Explanation  of  a  proposed  construction  of 
Zenith  Sector :  addressed  to  the  Board 
of  Visitors  of  the  Royal  Observatory, 
.  Greenwich. 

1848  Oct.  14     On  the  Construction  of  Chinese  Balls. 

1849  Description  of  the  Instruments  and  Process 

used  in  the  Photographic  self-registra- 
tion of  the  Magnetical  and  Meteorologi- 
cal Instruments  at  the  Royal  Observa- 
tory, Greenwich. 

1849  Description  of  the  Altitude  and  Azimuth 

Instrument  erected  at  the  Royal  Obser- 
vatory, Greenwich,  in  the  year  1847. 

1849  Astronomy.  (Tract  written  for  the  Scien- 

tific Manual.) 

1849  Mar.  9  Substance  of  the  Lecture  delivered  by  the 
Astronomer  Royal  on  the  large  Reflecting 
Telescopes  of  the  Earl  of  Rosse  and  Mr 
Lassell. 

1849  June         On  a  difficulty  in  the  Problem  of  Sound. 

1849  June  2  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1849  June  8  On  Instruments  adapted  to  the  Measure  of 
small  Meridional  Zenith  Distances. 

1849  Nov.  9  Results  of  the  Observations  made  by  the 
Rev.  Fearon  Fallows  at  the  Royal  Ob- 
servatory, Cape  of  Good  Hope,  in  the 
years  1829,  1830,  1831. 

1849  Nov.  9  On  Bell's  Calculating  Machine,  and  on 
Lord  Rosse's  Telescope. 

1849  Nov.  10  On  the  Exodus  of  the  Israelites. 


Where  published. 
Phil.  Mag. 

Camb.  Phil.  Soc. 


R.  Astr.  Soc. 
(Memoirs.) 


Athenaeum. 


R.  Astr.  Soc. 
(Month.  Not.) 


Phil.  Mag. 


R.  Astr.  Soc. 

(Month.  Not.) 
R.  Astr.  Soc. 
(Memoirs.) 


R.  Astr.  Soc. 

(Month.  Not.) 
Athenaeum. 


PRINTED   PAPERS  BY  G.   B.   AIRY. 


381 


Date  when  read 
or  published.  Title  of  Paper.  Where  published. 

1849  Dec.  14  On  the  Method  of  observing  and  recording    R.  Astr.  Soc. 

Transits,  lately  introduced  in  America,  &c.         (Month.  Not.) 

1850  Jan.  10  On  a  problem  of  Geodesy.  Phil.  Mag. 
1850  Feb.  8     Address  on  presenting  the   Medal  of  the     R.  Astr.  Soc.  . 

R.  Astr.  Soc.  to  M.  Otto  von  Struve.  (Month.  Not.) 

1850  Mar.  15  On  the  Present  State  and  Prospects  of  the     R.  Inst. 
Science  of  Terrestrial  Magnetism. 

1850  Mar.  16  On  the  Exodus  of  the  Israelites.  Athenaeum. 

1850  Mar.  30  On  the  Exodus  of  the  Israelites.  Athenaeum. 

1850  May  10  Statement  concerning  Assistance  granted     R.  Astr.  Soc. 

by  the  Admiralty  to  Hansen — Also  on        (Month.  Not.) 

Henderson's  numbers  for  the  teeth   of 

wheels. 

1850  May  10  On  the  Weights  to  be  given  to  the  sepa-     R.  Astr.  Soc. 
rate  Results  for  Terrestrial  Longitudes,        (Memoirs.) 
determined  by  the  Observation  of  Tran- 
sits of  the  Moon  and  Fixed  Stars. 

1850  June  i     Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1850  June  14  Letter  from  Hansen  on  his  Lunar  Tables.—     R.  Astr.  Soc. 

Valz  on  an  arrangement  of  double-image        (Month.  Not.) 
micrometer.— On    the    Computation    of 
Longitude  from  Lunar  Transits. 

1850  Dec.  13  On  a  Method  of  regulating  the  Clock-work     R.  Astr.  Soc. 

for  Equatoreals.  (Month.  Not.) 

1850  Dec.  13  Supplement  to  a  Paper  "On  the  Regulation     R.  Astr.  Soc. 
of  the  Clock-work  for  effecting  Uniform        (Memoirs.) 
Movement  of  Equatoreals." 

1850  Dec.  27  On  the  Relation  of  the  Direction  of  the     Phil.  Trans. 

Wind  to  the  Age  of  the  Moon,  as  inferred 
from  Observations  made  at  the  Royal 
Observatory,  Greenwich,  from  1840  Nov. 
to  1847  Dec. 

1851  Jan.  14    Remarks  on  Mr  Wyatt's  Paper  on  the  Con-     Inst.  C.  E. 

struction  of  the  Building  for  the  Exhibi-          (Minutes.) 
tion  of  the  Works  of  Industry  of  all  Na- 
tions in  1851. 

1851  Feb.  15  Address  on  presenting  the  Medal  of  the     R.  Astr.  Soc. 

R.     Astr.     Soc.    to     Dr    Annibale     de         (Month.  Not.) 
Gasparis. 

1851  Mar.  28  Letter  to  Professor  Challis  regarding  the 
Adams  Prize. 

1851  Mar.  29  On  Caesar's  Place  of  Landing  in  Britain.          Athenaeum. 

1851  Suggestions  to  Astronomers  for  the  Obser-     Brit.  Assoc. 


382 


APPENDIX. 


Date  when  read 
or  published. 


Title  of  Paper. 


vation  of  the  Total  Eclipse  of  the  Sun  on 
July  28,  1851. 

1851  Apr.  n  On  the  Determination  of  the  probable  Sta- 
bility of  an  Azimuth al  Circle  by  Observa- 
tions of  Stars  and  of  a  permanent  Colli- 
mator. 

1 85 1  May  2  On  the  Total  Solar  Eclipse  of  1 85 1,  July  28. 
(Lecture.) 

1851  May  9  On  the  Vibration  of  a  Free  Pendulum  in  an 
Oval  differing  little  from  a  Straight  Line. 

1851  June  7  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

185 1  July  2  The  President's  Address  to  the  Twenty-first 
Meeting  of  the  British  Association  for 
the  Advancement  of  Science,  Ipswich. 

1851  Oct.  17  On  Julius  Caesar's  Expedition  against  Eng- 
land, in  relation  to  his  places  of  de- 
parture and  landing. 

1851  Nov.  14  Account  of  the  Total  Eclipse  of  the  Sun  on 
1851,  July  28,  as  observed  at  Gottenburg, 
at  Christiania,  and  at  Christianstadt. 

1851  Dec.  13   On  the  Geography  of  the  Exodus. 

1852  Jan.  9      On  the  Solar  Eclipse  of  July  28,  1851. 

1852  On  the  Place  of  Caesar's  Departure  from 

Gaul  for  the  Invasion  of  Britain,  and 
the  Place  of  his  Landing  in  Britain, 
with  an  Appendix  on  the  Battle  of 
Hastings. 

1852  On  a  New  Method  of  computing  the  Per- 

turbations of  Planets,  by  J.  F.  Encke — 
translated  and  illustrated  with  notes  by 
G.  B.  Airy. 

1852  June  5     Report  of  the  Astronomer  Royal  to  the 

Board  of  Visitors. 

1853  Feb.  3     On  the  Eclipses   of  Agathocles,   Thales, 

and  Xerxes. 

1853  Feb.  4  Lecture  on  the  results  of  recent  calcula- 
tions on  the  Eclipse  of  Thales  and 
Eclipses  connected  with  it. 

1853  May  3  Address  to  the  Individual  Members  of  the 
Board  of  Visitors  of  the  Royal  Observa- 
tory, Greenwich.  (Lunar  Reductions.) 

1853  May  14   On  Decimal  Coinage. 


Where  published. 


R.  Astr.  Soc. 
(Month.  Not.) 


R.  Inst. 

R.  Astr.  Soc. 
(Memoirs.) 

Athenaeum. 
Naut.  Mag. 


R.  Astr.  Soc. 
(Memoirs.) 

Athenaeum. 
[R.  Astr.  Soc. 
I     (Month.  Not.) 

Soc.  of  Antiq. 
(Memoirs.) 


Naut.  Aim.  1856, 
App. 


Phil.  Trans. 
R.  Inst. 


Athenaeum. 


PRINTED   PAPERS   BY  G.   B.  AIRY. 


383 


Date  when  read 
or  published. 


Title  of  Paper. 


1853  June  4  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1853  June  Lecture  on  the  Determination  of  the  Lon- 
gitude of  the  Observatory  of  Cambridge 
by  means  of  Galvanic  Signals. 

1853  Sept.  10  On  Decimal  Coinage. 

1853  Dec.  14  Description  of  the  Transit  Circle  of  the 
Royal  Observatory,  Greenwich.  (App. 
Gr.  Observ.  1852.) 

1853  Dec.  14  Regulations    of   the    Royal   Observatory, 

Greenwich.     (App.  Gr.  Observ.  1852.) 

1854  Jan.  14    On  the  Telegraphic  Longitude  of  Brussels. 
1854  Feb.  10  Address  on  presenting  the  Gold  Medal  of 

the  R.  Astr.  Soc.  to  Mr  Charles  Riimker. 

1854  Feb.  25  On  Reforms  in  the  University  of  Cam- 
bridge. 

1854  Apr.  15    Letters  relating  to  "The  Late  M.  Mauvais." 

1854  June  3  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1854  Sept.       The  Deluge. 

1854  Oct.  28  On  the  Correction  of  the  Compass  in  Iron 
Ships.  (Scoresby's  Experiments.) 

1854  Nov.  10  On  the  Difference  of  Longitude  between 

the  Observatories  of  Brussels  and  Green- 
wich, as  determined  by  Galvanic  Signals. 

1855  Jan.  i      Lecture   at   S.  Shields  on   the   Pendulum 

Experiments  in  the  Harton  Pit,  and 
Letter  on  the  Results. 

1855  Feb.  2  Lecture  on  the  Pendulum  Experiments 
lately  made  in  the  Harton  Colliery  for 
ascertaining  the  mean  Density  of  the 
Earth. 

1855  Feb.  3  On  the  Correction  of  the  Compass  in  Iron 
Ships.  (Remarks  on  Dr  Scoresby's  In- 
vestigations.) 

1855  Address  on  presenting  the  Medal  of  the 

R.  Astr.  Soc.  to  the  Rev.  William  Rutter 
Dawes. 

1855  Feb.  15  On  the  Computation  of  the  Effect  of  the 
Attraction  of  Mountain  Masses,  as  dis- 
turbing the  Apparent  Astronomical  Lati- 
tude of  Stations  in  Geodetic  Surveys. 

1855  June  2  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 


Where  published. 


R.  Astr.  Soc. 
(Month.  Not.) 

Athenaeum. 


Athenaeum. 
R.  Astr.  Soc. 

(Month.  Not.) 
Athenaeum. 

Liter.  Gaz. 


Private. 
Athenaeum. 

R.  Astr.  Soc. 
(Memoirs.) 


R.  Inst. 


Athenaeum. 


R.  Astr.  Soc. 
(Month.  Not.) 

Phil.  Trans. 


APPENDIX. 


Date  when  read 
or  published. 


Title  of  Paper. 


1855  Oct.  18  Address  to  the  Individual  Members  of  the 
Board  of  .Visitors  of  the  Royal  Observa- 
tory, Greenwich.  (^Tquatoreal.) 

1855  Nov.  21  Remarks  upon  certain  Cases  of  Personal 
Equation  which  appear  to  have  hitherto 
escaped  notice,  accompanied  with  a  Table 
of  Results. 

1855  Nov.  22  Discussion  of  the  Observed  Deviations  of 
the  Compass  in  several  Ships,  Wood- 
built  and  Iron-built :  with  a  General 
Table  for  facilitating  the  examination  of 
Compass-Deviations. 

1855  Description  of  the  Reflex  Zenith  Tube  of 

the  Royal  Observatory,  Greenwich.  (App. 
to  the  Greenwich  Obs.  for  1854.) 

1856  Jan.  9      On   Professor   Peirce's   Criterion  for   dis- 

cordant observations. 

1856  Jan.  24  Account  of  Pendulum  Experiments  under- 
taken in  the  Hartori  Colliery,  for  the 
purpose  of  determining  the  Mean  Den- 
sity of  the  Earth. 

1856  June  7  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1856  Aug.  25   On  Scheutz's  Calculating  Machine. 

1856  Aug.  30  Science  and  the  Government.     (Reply  to 

statements  in  the  Morning  Chronicle 
about  the  instrumental  equipment  of  the 
Royal  Observatory.) 

1857  May  8     On  the  Means  which  will  be  available  for 

correcting  the  Measure  of  the  Sun's  Dis- 
tance in  the  next  twenty-five  years. 
1857  May  12    Knowledge    expected    in    Computers   and 

Assistants  in  the  Royal  Observatory. 
1857  June  6     Report  of  the  Astronomer   Royal  to  the 

Board  of  Visitors. 
1857  June  12  On  the  Eclipse  of  Agathocles,  the  Eclipse 

at  Larissa,  and  the  Eclipse  of  Thales. 

With  an  Appendix  on  the   Eclipse  of 

Stiklastad. 
1857  June  1 8  Account  of  the  Construction  of  the  New 

National  Standard  of  Length,  and  of  its 

principal  copies. 
1857  Dec.  5     Letter  to  the  Vice-Chancellor  of  Cambridge 

University  regarding  Smith's  Prizes. 


Where  published. 


R.  Astr.  Soc. 
(Month.  Not.) 


Phil.  Trans. 


Astr.  Journ. 

(Cambr.) 

Phil.  Trans. 


Phil.  Mag. 
Athenaeum. 


R.  Astr.  Soc. 
(Month.  Not.) 


R.  Astr.  Soc. 
(Memoirs.) 

Phil.  Trans. 


PRINTED    PAPERS   BY  G.   B.   AIRY. 


385 


Date  when  read 
or  published. 

1857  Dec.  7 


Title  of  Paper. 

On  the  Substitution  of  Methods  founded 
Ordinary    Geometry    for     Methods 


on 


based  on  the  General  Doctrine  of  Pro- 
portions, in  the  treatment  of  some  Geo- 
metrical Problems. 

1857  Description  of  the  Galvanic  Chronographic 

Apparatus  of  the  Royal  Observatory, 
Greenwich. 

1858  Mar.  8     Suggestions  for  Observation  of  the  Annular 

Eclipse  of  the  Sun  on  1858,  March  14-15. 

1858  Mar.  12  Note  on  Oltmann's  Calculation  of  the 
Eclipse  of  Thales.  Also  On  a  Method 
of  very  approximately  representing  the 
Projection  of  a  Great  Circle  upon  M cr- 
eator's Chart. 

1858  May        The  Atlantic  Cable  Problem. 

1858  May  20  Report  of  the  Ordnance  Survey  Commis- 
sion ;  together  with  Minutes  of  Evidence 
and  Appendix. 

1858  June  5  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1858  June  1 6  On  the  Mechanical  Conditions  of  the  De- 
posit of  a  Submarine  Cable. 

1858  July  Instructions  and  Chart  for  Observations  of 
Mars  in  right  ascension  at  the  Opposi- 
tion of  1 860  for  obtaining  the  Measure  of 
the  Sun's  Distance. 

1858  Aug.  20  On  the  Advantageous  Employment  of 
Stereoscopic  Photographs  for  the  repre- 
sentation of  Scenery. 

1858  Nov.  6  On  the  "Draft  of  Proposed  New  Statutes 
for  Trinity  College,  Cambridge." 

1858  Nov.  20  Letter  to  the  Vice-Chancellor  of  the  Uni- 
versity of  Cambridge,  offering  the  Sheep- 
shanks Endowment. 

1858  Dec.  6     Suggestion   of  a   Proof   of  the  Theorem 

that  Every  Algebraic  Equation  has  a 
Root. 

1859  Manual  of  Astronomy — for  the  Admiralty. 
1859  Feb.  i      Letter  to  Lord  Monteagle  relating  to  the 

Standards  of  Weights  and  Measures. 
1859  Feb.  4     Remarks  on  Mr  Cayley's  Trigonometrical 
Theorem,  and  on   Prof.  Challis's  Proof 
that  Equations  have  Roots. 

A.  B. 


Where  published. 
Camb.  Phil.  Soc. 


Gr.  Obs.  1856, 
App. 


R.  Astr.  Soc. 
(Month.  Not.) 


Naut.  Mag. 


Phil.  Mag. 

R.  Astr.  Soc. 
(Special.) 


Photog.  Notes. 
Athenaeum. 

Camb.  Phil.  Soc. 

Parly.  Paper. 
Phil.  Mag. 

25 


386 


APPENDIX. 


Date  when  read 
or  published. 


Title  of  Paper. 


1859  Mar.  ii  On  the  Movement  of  the  Solar  System  in 
Space. .. 

1859  Apr.  8  On  the  Apparent  Pr6jection  of  Stars  upon 
the  Moon's  Disc  in  Occultations.  Also 
Comparison  of  the  Lunar  Tables  of 
Burckhardt  and  Hansen  with  Observa- 
tions of  the  Moon  made  at  the  Royal 
Observatory,  Greenwich. 

1859  Apr.  8  On  the  Apparent  Projection  of  Stars  upon 
the  Moon's  Disc  in  Occultations. 

1859  June  4  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1859  June  10  Abstract  of  Maxwell's  Paper  "On  the  Sta- 
bility of  the  Motion  of  Saturn's  Rings." 

1859  July  8  Corrections  of  the  Elements  of  the  Moon's 
Orbit,  deduced  from  the  Lunar  Observa- 
tions made  at  the  Royal  Observatory  of 
Greenwich  from  1750  to  1851. 

1859  Sept.  10  On  the  Invasion  of  Britain  by  Julius  Caesar. 
(Answer  to  Mr  Lewin.) 

1859  Nov.  12  On  Iron  Ships— The  Royal  Charter.  (An- 
swer to  Archibald  Smith's  Remarks.) 

1859  Nov.  Circular  requesting  observations  of  small 
Planets. 

1859  Dec.  9  Notice  of  the  approaching  Total  Eclipse  of 
the  Sun  of  July  18,  1860,  and  suggestions 
for  observation. 

1859  Dec.  12  Supplement  to  A  Proof  of  the  Theorem 

that  Every  Algebraic  Equation  has  a 
Root. 

1860  Jan.  13    Description  of  the  New  Equatoreal  at  the 

Royal  Observatory,  Greenwich.  Also 
Abstract  of  an  Essay  by  Gen.  T.  F.  de 
Schubert  on  the  Figure  of  the  Earth. 

1860  Jan.  28  On  the  Claudian  or  Plautian  Invasion  of 
Britain. 

1860  Feb.  2  Examination  of  Navy  2-foot  Telescopes  at 
the  Royal  Observatory,  Greenwich,  1860, 
Jan.  31  to  Feb.  2. 

1860  Feb.  ii  Report  on  the  Instrumental  Equipments 
of  the  Exchequer  Office  of  Weights  and 
Measures,  as  regards  the  means  for  pre- 
venting Fraud  in  the  Sale  of  Gas  to  the 
Public;  and  on  the  Amendments  which 


Where  published. 

R.  Astr.  Soc. 

(Memoirs.) 
R.  Astr.  Soc. 

(Month.  Not.) 


R.  Astr.  Soc. 
(Memoirs.) 


R.  Astr.  Soc. 

(Month.  Not.) 
R.  Astr.  Soc. 

(Memoirs.) 


Athenaeum. 
Athenaeum. 


R.  Astr.  Soc. 
(Month.  Not.) 

Camb.  Phil.  Soc. 


R.  Astr.  Soc. 
(Month.  Not.] 


Athenaeum. 


Ho.  of  Commons. 
(Parly.  Paper.) 


PRINTED    PAPERS   BY  G.    B.   AIRY. 


387 


Date  when  read 
or  published.  Title  of  Paper.  Where  published. 

may  be  required  to  the  existing  Legisla- 
tion on  that  subject. 
1860  Mar.  9     Address  on  the  approaching  Solar  Eclipse     R.  Astr.  Soc. 

of  July  1 8,  1860,  &c.  (Month.  Not.) 

1860  May  10   Correspondence  between  the  Lords  Com-     Ho.  of  Commons. 

missioners  of  Her   Majesty's  Treasury,       (Parly.  Paper.) 

&c.,  and  the  Astronomer  Royal,  relating 

to  Gas  Measurement,  and  the  Sale   of 

Gas  Act. 
1860  June  2     Report   of  the  Astronomer   Royal  to   the 

Board  of  Visitors.     And  Address  to  the 

Members  of  the  Board  in  reference  to 

Struve's  Geodetic  suggestions. 
1860  June  7     Correspondence    regarding   the    Grant   of 

;£iooo  to   Prof.  Hansen   for  his  Lunar 

Tables. 
1860  Sept.  13  Remarks   on   a   Paper  entitled   "On   the 

Polar  Distances  of  the  Greenwich  Transit 

Circle,    by   A.    Marth."      Addressed    to 

the  Members  of  the  Board  of  Visitors. 
1860  Sept.  22  On  Change  of  Climate,  in  answer  to  cer-    Athenaeum. 

tain  speculations  by  Sir  Henry  James. 
1860  Oct.  20    Circular    relating    to    the    distribution    of 

Greenwich  Observations  and  other  pub- 
lications of  the  Royal  Observatory. 
1860  Nov.  9     Account  of  Observations  of  the  Total  Solar     R.  Astr.  Soc. 

Eclipse  of  1860,  July  18,  made  at  Herefia,        (Month.  Not.) 

near  Miranda  de  Ebro ;  &c.  &c. 

1860  Nov.  17  On  Change  of  Climate :  further  discussion.     Athenaeum. 
1860  Letters  on  Lighthouses,  to  the  Commission 

on  Lighthouses. 

1860  Dec.  14   Note  on  the  translation  of  a  passage  in  a     R.  Astr.  Soc. 

letter  of  Hansen's  relating  to  coefficients.         (Month.  Not.) 

1 86 1  Feb.  9     On  the  Temperature-correction  of  Syphon     Athenaeum. 

Barometers. 
1861  March     Results  of  Observations  of  the  Solar  Eclipse    R.  Astr.  Soc. 

of  1860  July  18  made  at  the  Royal  Obser-  (Month.  Not.) 
vatory,  Greenwich,  for  determination  of 
the  Errors  of  the  Tabular  Elements  of 
the  Eclipse.  Also  Suggestion  of  a  new 
Astronomical  Instrument,  for  which  the 
name  "Orbit-Sweeper 'Ms  proposed..  Also 
Theory  of  the  Regulation  of  a  Clock  by 
Galvanic  Currents  acting  on  the  Pen- 
dulum. 25 — 2 


388 


APPENDIX. 


Date  when  read 
or  published. 


Title  of  Paper. 


1 86 1  June  i     Report  of  the  Astronomer  Royal  to  the 

Board  of  Visitors. 
1861  June  5     On  a  supposed  FaiKire  of  the  Calculus  of 

Variations. 
1861  July         Report  of  a  Committee  of  the  R.  Soc.  on 

the    advisability    of    re-measuring,  the 

Indian  Arc  of  Meridian. 
1 86 1  Sept.  21  Lecture  at  Manchester  on  the  Great  Solar 

Eclipse  of  July  18,  1860. 
1 86 1  Sept.  21  The  same  Lecture. 
1861  Oct.         Examination   Paper  for  the  Sheepshanks 

Exhibition. 
1861  Nov.  i     Translation  of  Dr  Lament's  Paper  "  On  the 

most  Advantageous  Form  of  Magnets." 
1 86 1  Nov.  8     Note  on  a  Letter  received  from  Hansen  on 

the  Lunar  Theory.     Also  Discussion  of 

a  Result  deduced  by  Mr  D'Abbadie  from 

Observations  of  the  Total  Solar  Eclipse 

of  1860,  July  1 8. 
1861  Nov.  16  Instructions  for  observing  the  Total  Eclipse 

of  the  Sun  on  December  31. 
1 86 1  Dec.        On  a  Projection  by  Balance  of  Errors  for 

Maps. 

1861  Dec.  28  On  the  Circularity  of  the  Sun's  Disk.    Also 

Table  of  Comparative  Number  of  Obser- 
vations of  Small  Planets. 

1862  Jan.         On    the    Direction   of   the   Joints   in  the 

Faces  of  Oblique  Arches. 
1862  Mar.  15  Review  of  "An  Historical  Survey  of  the 

Astronomy  of  the  Ancients"  by  the  Rt 

Hon.  Sir  G.  Cornewall  Lewis. 
1862  Apr.  24   Notes  for  the  Committee  on  Weights  and 

Measures,  1862. 
1862  May  15   On  the  Magnetic  Properties  of  Hot-Rolled 

and  Cold- Rolled  Malleable  Iron. 
1862  June  7     Report   of  the  Astronomer  Royal  to  the 

Board  of  Visitors. 

1862  June  24  Evidence  given  before   the    Select   Com- 
mittee on  Weights  and  Measures. 
1862  Oct.  4      Biography  of  G.  B.  Airy  (probably  in  part 

based  upon  data  supplied  by  himself). 
1862  Oct.  ii    Abstract  of  Paper  "On  the  Strains  in  the 

Interior  of  Beams  and  Tubular  Bridges." 
1862  Oct.  ii    Translation  of  a  Letter  from  Prof.  Lamont 

on  Dalton's  Theory  of  Vapour,  &c. 


Where  published. 

Phil.  Mag. 

R.  Soc.     (Proc.) 

Athenaeum. 
London  Review. 

Phil.  Mag. 

R.  Astr.  Soc. 
(Month.  Not.) 


Phil.  Mag. 

R.  Astr.  Soc. 
(Month.  Not.) 

Phil.  Mag. 
Athenaeum. 


Phil.  Trans. 


London  Review. 
Athenaeum. 
Phil.  Mag. 


PRINTED   PAPERS   BY   G.   B.   AIRY. 


389 


Date  when  read 
or  published. 


Title  of  Paper. 


1862  Nov.  6     On  the  Strains  in  the  Interior  of  Beams. 

1862  Nov.  Correspondence  with  Sabine  concerning 
his  attack  on  the  Greenwich  Magnetic 
Observations.  (Confidentially  communi- 
cated to  the  Board  of  Visitors.) 

1862  Nov.  21  Evidence  given  before  the  Public  Schools 
Commission. 

1862  Nov.  Abstract  of  M.  Auwers's  Paper  on  the 
proper  motion  of  Procyon,  and  Note  on 
same. 

1862  Dec.        Abstract    of    Mr   Safford's    Paper   on   the 

Proper  Motion  of  Sirius.  Also  on  the 
Forms  of  Lenses  proper  for  the  Negative 
Eye-pieces  of  Telescopes.  Also  on  the 
measurements  of  the  Earth,  and  the 
dimensions  of  the  Solar  System.  Also 
on  Fringes  of  Light  in  Solar  Eclipses. 

1863  Jan.         Address  to  the  Board  of  Visitors  on  a  fur- 

ther attack  by  Sabine  on  the  Greenwich 
Magnetic  Observations  (confidential). 

1863  Jan.  9  On  the  Observations  of  Saturn  made  at 
Pulkowa  and  Greenwich. 

1863  Feb.  24  Report  to  the  Board  of  Trade  on  the 
Proposed  Lines  of  Railway  through 
Greenwich  Park. 

1863  Mar.  2  Determination  of  the  Longitude  of  Valencia 
in  Ireland  by  Galvanic  Signals  in  the 
summer  of  1862  (App.  III.  to  the  Gr. 
Astr.  Obsns.  1862). 

1863  Mar.  13  On  the  Movement  of  the  Solar  System  in 
Space,  deduced  from  the  Proper  Motions 
of  1167  Stars.  By  Edwin  Dunkin  (for 
G.  B.  A.). 

1863  Mar.  13  On  the  Visibility  of  Stars  in  the  Pleiades 
to  the  unarmed  eye. 

1863  Mar.  21  On  Marriage  Odes. 

1863  Apr.  9  Further  Report  as  to  the  Probable  Effects 
of  the  London,  Chatham  and  Dover 
Railway  on  the  Royal  Observatory  in 
Greenwich  Park. 

1863  Apr.  10  Determination  of  the  Sun's  Parallax  from 
observations  of  Mars  during  the  Oppo- 
sition of  1862.  By  E.  J.  Stone  (for 
G.  B.  A.).  Also  Remarks  on  Struve's 


Where  published. 
Phil.  Trans. 


R.  Astr.  Soc. 
(Month.  Not.) 

R.  Astr.  Soc. 
(Month.  Not.) 


R.  Astr.  Soc. 
(Month.  Not.) 


R.  Astr.  Soc. 
(Memoirs.) 


R.  Astr.  Soc. 

(Month.  Not.) 
Athenaeum. 


R.  Astr.  Soc. 
(Month.  Not.) 


390 


APPENDIX. 


Date  when  read 
or  published. 


Title  of  Paper. 


Where  published. 


account  of  a  Local  deviation  in  the  di- 
rection of  Gravity,  near  Moscow.  Also 
an  Account  of  ah  apparatus  for  the 
observation  of  the  spectra  of  stars,  and 
results  obtained. 

1863  Apr.  23  On  the  Diurnal  Inequalities  of  Terrestrial 
Magnetism,  as  deduced  from  observa- 
tions made  at  the  Royal  Observatory, 
Greenwich,  from  1841  to  1857. 

1863  May  8  On  the  Discordance  between  the  Results 
for  Zenith-Distances  obtained  by  Direct 
Observation,  and  those  obtained  by 
Observation  by  Reflection  from  the  Sur- 
face of  Quicksilver. 
1863  June  6  Report  of  the  Astronomer  Royal  to  the 

Board  of  Visitors. 

1863  July  2  On  the  Amount  of  Light  given  by  the 
Moon  at  the  greatest  stage  in  the  Ex- 
centrically-total  Eclipse,  1863,  June  i. 
1863  Aug.  Plan  of  the  Buildings  and  Grounds  of  the 
Royal  Observatory,  Greenwich,  with 
Explanation  and  History. 

1863  Sept.  5  On  the  origin  of  the  apparent  luminous 
band  which,  in  partial  eclipses  of  the 
Sun,  has  been  seen  to  surround  the 
visible  portion  of  the  Moon's  limb. 

fiS63  Sept.  5  On   the    Invasions    of   Britain   by   Julius 
\i863  Oct.  3       Caesar. 

1863  Oct.  17  The  Earthquake  as  observed  from  Green- 
wich. 

1863  Nov.  On  the  Numerical  Expression  of  the  De- 
structive Energy  in  the  Explosions  of 
Steam- Boilers,  &c. 

1863  Nov.  13  Convention  arranged  between  M.  LeVerrier 
and  the  Astronomer  Royal  for  meridi- 
onal observations  of  the  small  Planets, 
&c. 

1863  Nov.  13  Translation  of  Hansen's  Paper  "Calcula- 
tion of  the  Sun's  Parallax  from  the 
Lunar  Theory,"  with  Notes  by  G.  B.  A. 
1863  Dec.  17  First  Analysis  of  177  Magnetic  Storms, 
registered  by  the  Magnetic  Instruments 
in  the  Royal  Observatory,  Greenwich, 
from  1841  to  1857. 


Phil.  Trans. 


R.  Astr.  Soc. 
(Memoirs.) 


R.  Astr.  Soc. 
(Month.  Not.) 


R.  Astr.  Soc. 
(Month.  Not.) 


Athenaeum. 
Athenaeum. 
Phil.  Mag. 


R.  Astr.  Soc. 
(Month.  Not.) 


R.  Astr.  Soc. 
(Month.  Not.) 

Phil.  Trans. 


PRINTED   PAPERS   BY   G.   B.   AIRY. 


391 


Date  when  read 
or  published. 


Title  of  Paper. 


1864  Jan.  8  Pontecoulant's  Paper  "  Sur  le  Coefficiant 
de  1'Equation  Parallactique  deduit  de  la 
Theorie,"  with  Notes  by  G.  B.  A. 

1864  Jan.  26  Remarks  on  Redman's  Paper  on  the  East 
Coast  (Chesil  Bank,  &c.). 

1864  Mar.  10  Note  on  a  Passage  in  Capt.  Jacob's 
"  Measures  of  Jupiter,"  &c. 

1864  Mar.  ii  Notes  for  the  Committee  on  Weights  and 
Measures,  1862. 

1864  Mar.  17  On  a  Method  of  Slewing  a  Ship  without 
the  aid  of  the  Rudder. 

1864  Apr.  5  Comparison  of  the  Chinese  Record  of  Solar 
Eclipses  in  the  Chun  Tsew  with  the 
Computations  of  Modern  Theory. 

1864  June  4  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1864  June  10  On  the  Transit  of  Venus,  1882,  Dec.  6. 

1864  June  10  On  the  bright  band  bordering  the  Moon's 
Limb  in  Photographs  of  Eclipses. 

1864  Notes  on  Methods  of  Reduction  appli- 

cable to  the  Indian  Survey. 

1864  Sept.  3    A  Visit  to  the  Corryvreckan. 

1864  Sept.  29  Examination   Paper  for  the  Sheepshanks 

Scholarship. 

1865  Jan.  13   Comparison  of  the  Transit-Instrument  in 

its  ordinary  or  reversible  form  with  the 
Transit-Instrument  in  its  non-reversi- 
ble form,  as  adopted  at  Greenwich,  the 
Cape  of  Good  Hope,  and  other  Observa- 
tories. 

1865  Mar.  9  Syllabus  of  a  course  of  three  Lectures  on 
"  Magnetical  Errors,  &c.,  with  special 
reference  to  Iron  Ships  and  their  Com- 
passes," delivered  at  the  South  Kensing- 
ton Museum. 

1865  Apr.  i  Remarks  on  Mr  Ellis's  Lecture  on  the 
Greenwich  System  of  Time  Signals. 

1865  Apr.  i  Free  Translation  of  some  lines  of  Virgil, 
"  Cithara  crinitus  lopas,"  &c. 

1865  June  3  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1865  June  17  Note  on  my  Recommendation  (in  1839) 
of  Government  Superintendence  of  the 


Where  published. 

R.  Astr.  Soc. 
(Month.  Not.) 

Inst.  C.  E. 

(Minutes.) 
R.  Astr.  Soc. 

(Month.  Not.) 
Ho.  of  Comm. 

(Parly.  Paper.) 
Inst.  Nav.  Arch. 

R.  Astr.  Soc. 
(Month.  Not.) 


R.  Astr.  Soc. 

(Month.  Not) 
R.  Astr.  Soc. 

(Month.  Not.) 


Athenaeum. 


R.  Astr.  Soc. 

(Month.  Not.) 


Horolog.  Journ. 
Athenaeum. 

Athenaeum. 


392 


APPENDIX. 


Date  when  read 
or  published.  Title  of  Paper.  Where  published. 

Compasses  of  Iron  Ships.  Also  Note  on 
the  birthplace  of  Thomas  Clarkson. 

1865  July        On  Hemiopsy.  Phil.  Mag. 

1865  Aug.  22  On  the  Value  of  the  Moon's  Semidiameter     R.  Astr.  Soc. 

as    obtained  by  the    Investigations    of        (Month.  Not.) 
Hugh   Breen,   Esq.,   from   Occultations 
observed  at  Cambridge  and  Greenwich. 

1865  Sept.  16  On  "The  Land  of  Goshen"—  Reply  to  "A    Athenaeum. 
Suffolk  Incumbent." 

1865  Oct.  21  Address  of  the  Astronomer  Royal  to  the  in- 
dividual members  of  the  Board  of  Visi- 
tors. (On  improved  Collimators.) 

1865  Oct.  23   Note  on  an  Error  of  Expression  in  two  pre-     R.  Astr.  Soc. 

vious    Memoirs.      Also  Description  and        (Month.  Not.) 

History  of  a  Quadrant  made  by  Abraham 

Sharp. 

1865  Nov.  ii  On  the  Possible  Derivation  of  the  National    Athenaeum. 
Name  "Welsh." 

1865  Essays  on  the  Invasion  of  Britain  by  Julius     Private. 

Caesar;  The  Invasion  of  Britain  by  Plau- 
tius,  and  by  Claudius  Caesar ;  The  Early 
Military  Policy  of  the  Romans  in  Britain; 
The  Battle  of  Hastings.  (With  corr.) 

1866  Mar.  10  On  "The  Compass  in  Iron  Ships."    Objec-    Athenaeum. 

tions  to  passages  in  a  Lecture  by  Archi- 
bald Smith. 

1866  Apr.  13  On  the  Supposed  Possible  Effect  of  Fric-     R.  Astr.  Soc. 

tion  in  the  Tides,  in  influencing  the  Ap-  (Month.  Not.) 
parent  Acceleration  of  the  Moon's  Mean 
Motion  in  Longitude.  Also  on  a  Method 
of  Computing  Interpolations  to  the 
Second  Order  without  Changes  of  Alge- 
braic Sign. 

1866  June  2  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1866  July  17   Papers  relating  to  Time   Signals   on  the     Ho.  of  Comm. 

Start  Point.  (Parly.  Paper.) 

1866  Sept.  i    On  the   Campaign   of  Aulus    Plautius    in    Athenaeum. 
Britain.     (Reply  to  Dr  Guest.) 

1866  Nov.  19  On  the  Continued  Change  in  an  Eye  af-     Camb.  Phil.  Soc. 
fected  with  a  peculiar  malformation. 

1866  Dec.        On  the   Simultaneous    Disappearance    of    R.  Astr.  Soc. 

Jupiter's  Satellites  in  the  year  1867.    Also         (Month.  Not.) 
Inference  from  the  observed  Movement 


PRINTED   PAPERS   BY   G.   B.   AIRY. 


393 


Date  when  read 
or  published. 


Title  of  Paper. 


Where  published. 


of  the  Meteors  in  the  appearance  of  1866, 

Nov.  13-14. 
1867  Jan.  i      Memorandum  for  the  consideration  of  the 

Commission  on  Standards.     (Policy  of 

introducing  Metrical  Standards.) 
1867  Jan.  12   On  Decimal  Weights  and  Measures. 
1867  Feb.  19  On  the  use  of  the  Suspension  Bridge  with 

Stiffened  Roadway  for  Railway  and  other 

Bridges  of  Great  Span. 
1867  Mar.  21  Computation  of  the  Lengths  of  the  Waves 

of  Light  corresponding  to  the  Lines  in 

the  Dispersion  Spectrum   measured  by 

Kirchhoff. 
1867  Mar.       Corresponding   Numbers   of  Elevation   in 

English  Feet,  and  of  Readings  of  Ane- 
roid or  Corrected  Barometer  in  English 

Inches. 
1867  Apr.  1 6   Remarks  on  Sir  W.  Denison's  Paper  on 

"The  Suez  Canal." 
1867  May  3     Statement  of  the  History  and  Position  of 

the  Blue-coat  Girls'  School,  Greenwich. 
1867  June  i     Report  of  the   Astronomer  Royal  to   the 

Board  of  Visitors. 
1867  June  14   On  Certain  Appearances  of  the  Telescopic 

Images  of  Stars  described  by  the  Rev. 

W.  R.  Dawes. 

1867  Dec.  13    Note  on  the  Total  Solar  Eclipse  of  1868, 

Aug.  17-18. 

1868  Biography  of  G.  B.  Airy.     (Probably  cor- 

rected by  himself.) 

1868  Jan.  4  Biography  (with  portrait)  of  G.  B.  Airy. 
(Probably  corrected  by  himself.) 

1868  Feb.  6  Comparison  of  Magnetic  Disturbances  re- 
corded by  the  Self-registering  Magneto- 
meters at  the  Royal  Observatory,  Green- 
wich, with  Magnetic  Disturbances  de- 
duced from  the  corresponding  Terrestrial 
Galvanic  Currents  recorded  by  the  Self- 
registering  Galvanometers  of  the  Royal 
Observatory. 

1868  Mar.  13  Address  of  the  Astronomer  Royal  to  the 
Individual  Members  of  the  Board  of  Visi- 
tors. (Number  of  Copies  of  Observa- 
tions.) 


Athenaeum. 
Inst.  C.  E. 
(Minutes.) 

Phil.  Trans. 


R.  Obs.  (Also 
Meteor.  Soc. 
Apr.  17,  1867.) 

Inst.  C.  E. 

(Minutes.) 
Private. 


R.  Astr.  Soc. 
(Month.  Not.) 

R.  Astr.  Soc. 
(Month.  Not.) 


111.  Lond.  News. 
Phil.  Trans. 


394 


APPENDIX. 


Date  when  read 
or  published. 


Title  of  Paper. 


Where  published. 


1868  June  6     Report   of  the  Astronomer  Royal  to  the 

Board  of  Visitors. 
1868  July  24   First    Report   of  the  "Commissioners    ap-     Parly.  Paper. 

pointed  to  enquire  into  The  Condition  of 

the  Exchequer  Standards. 

1868  Sept.  19  The  Inundation  at  Visp.  j.          Athenaeum. 

1868  Nov.  9     On  the  Factorial  Resolution  of  the  Trino-     Camb.  Phil.  Soc. 

mial  xn  -  2  cos  #.  a.  +  — -. 

1868  Dec.  10  On  the  Diurnal  and  Annual   Inequalities     Phil.  Trans. 

of    Terrestrial   Magnetism,   as   deduced 

from  Observations  made  at  the  Royal 

Observatory  from  1858  to  1863,  &c. 
1868  Dec.  ii   On  the  Preparatory  Arrangements  for  the     R.  Astr.  Soc. 

Observation  of  The  Transits  of  Venus        (Month.  Not.) 

1874  and  1882. 

1868  Dec.  12  On  the  Migrations  of  the  Welsh  Nations.        Athenaeum. 

1869  Mar.  8     Memorandum  by  the  Chairman   (on   the 

use  of  the  Troy  Weight)  for   the   con- 
sideration of  the  Members  of  the  Stan- 
dards Commission. 
1869  Apr.  3     Second  Report  of  the  Commissioners  ap-     Parly.  Paper. 

pointed  to  enquire  into  the  condition  of 

the   Exchequer  (now    Board   of  Trade) 

Standards.— The  Metric  System. 
1869  April       Syllabus  of  Lectures  on  Magnetism  to  be 

delivered  in  the  University  of  Cambridge. 
1869  Apr.  27    Remarks    on    Shelford's    Paper   "On   the     Inst.  C.  E. 

Outfall  of  the  River  Humber."  (Minutes.) 

1869  June  i     Memorandum  for  the  consideration  of  the 

Standards  Commission,  on  the  state  of 

the  Question  now  before  them  regarding 

the  suggested  Abolition  of  Troy  Weight. 
1869  June  5     Report  of  the  Astronomer   Royal  to  the 

Board  of  Visitors. 

1869  Supplementary  Memorandum  by  the  Astro- 

nomer Royal  on  the  proposed  Abolition 

of  Troy  Weight. 
1869  July  6     Correspondence  between  the  Treasury,  the     Ho.  of  Comm. 

Admiralty,  and  the  Astronomer  Royal,        (Parly.  Paper.) 

respecting  the  arrangements  to  be  made 

for   Observing  the    Transits   of  Venus, 

which  will  take  place  in  the  years  1874 

and  1882. 


PRINTED    PAPERS   BY   G.    B.   AIRY. 


395 


Date  when  read 
or  published.  Title  of  Paper.  Where  published. 

1869  Aug.  7     Note  on  Atmospheric   Chromatic  Disper-     R.  Astr.  Soc. 

sion  as  affecting  Telescopic  Observation,        (Month.  Not.) 
and  on  the  Mode  of  Correcting  it. 

1869  Oct.  19   Description  of  the  Great  Equatoreal  of  the 

Royal  Observatory,  Greenwich.  Green- 
wich Observations,  1868.  App. 

1870  Feb.  3     Note  on  an  Extension  of  the  Comparison     Phil.  Trans. 

of  Magnetic  Disturbances  with  Magnetic 
Effects  inferred  from  observed  Terres- 
trial Galvanic  Currents  ;  &c.  &c. 

1870  Apr.  8     On  the  question  of  a  Royal  Commission  for    Journ.  Soc.  Arts. 
Science. 

1870  May  2  Letters  to  the  First  Lord  of  the  Admiralty 
enclosing  Application  of  the  Assistants 
for  an  increase  of  Salaries. 

1870  May  13  On  Decimal  and  Metrical  Systems.  Journ.  Soc.  Arts. 

1870  June  4  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1870  Aug.  27  On  the  meaning  of  the  word  "  Whippultree."     Athenaeum. 

1870  Oct.  22    On  the  Locality  of  "  Paradise."  Athenauim. 

1870  Nov.  12  On  the  Locality  of  the  Roman  Gesoriacum.     Athenaeum. 

1870  Nov.  30  Recommendation    of    Prof.    Miller    for    a     R.  Soc.     (Proc.) 
Royal    Medal    of    the    Royal    Society. 
(Quoted  by  the  President.) 

1870  Revised  Edition  of  "  Astronomy."  Man.  Naut.  Sci. 

1871  Jan.  21    The  Burial  of  Sir  John  Moore.  Athenaeum. 
1871  Mar.  14  Letter  to  the  Hydrographer  of  the  Admiralty 

on  the  qualifications  and  claims  of  the 

Assistants  of  the  Royal  Observatory. 
1871  Apr.  5     Remarks  on  the  Determination  of  a  Ship's     R.  Soc.     (Proc.) 

Place  at  Sea. 
1871  May  2     Remarks  on  Samuelson's  Paper  "  Descrip-     Inst.  C.  E. 

tion  of  two  Blast  Furnaces,"  &c.  (Minutes.) 

1871  May  3     Note  on  Barometric  Compensation  of  the     Phil.  Mag. 

Pendulum. 
1871  June  3     Report   of  the  Astronomer   Royal  to  the 

Board  of  Visitors. 
1871  June  9     Remarks  on  Mr  Abbott's  observations  on     R.  Astr.  Soc. 

77  Argus.     Also  on  A.  S.  Herschel's  and        (Month.  Not.) 

J.  Herschel's  Mechanism  for  measuring 

Time  automatically  in  taking  Transits. 
1871  Erratum  in  Results  of  Greenwich  Obser-     R.  Astr.  Soc. 

vations   of   the   Solar   Eclipse   of   1860,         (Month.  Not.) 

July  1 8.     Also  Observations  of  the  Solar 


396 


APPENDIX. 


Date  when  read 
or  published.  Title  of  Paper.  Where  published. 

Eclipse  of  1870,  Dec.  21-22,  made  at  the 
Royal  Observatory,  Qreenwich. 

1871  Aug.         Investigation  of  the  LELW  of  the  Progress  of    Phil.  Mag. 
Accuracy  in  the  usual  process  for  Form- 
ing a  Plane  Surface. 

1871  Nov.  1 6  Corrections  to  the  Computed  Lengths  of    Phil.  Trans. 
Waves  of  Light  for  Kirchhoff 's  Spectral 
Lines. 

1871  On  a  supposed  alteration  in  the  amount  of    R.  Soc.     (Proc.) 

Astronomical  Aberration  of  Light,  pro- 
duced by  the  passage  of  the  Light 
through  a  considerable  thickness  of  Re- 
fracting Medium. 

1871  Nov.  29  Biography  of  G.  B.  Airy.     (Probably  cor-     Daily  Telegraph, 
rected  by  himself.) 

1871  Dec.  8     Note  on  a  special  point  in  the  determina-     R.  Astr.  Soc. 

tion  of  the  Elements  of  the  Moon's  Orbit        (Month.  Not.) 

from    Meridional    Observations    of   the 

Moon. 

1871  Dec.  26  Proposed  devotion  of  an  Observatory  to     R.  Astr.  Soc. 

observation  of  the  phenomena  of  Jupiter's        (Month.  Not.) 
Satellites. 

1872  Jan.         Address  to  the  Council  of  the  Royal  Society 

on  the  propriety  of  continuing  the  Grant 
to  the  Kew  Observatory  for  meteorologi- 
cal observations. 

1872  Feb.  8     Experiments  on   the   Directive   Power  of    Phil.  Trans, 
large  Steel  Magnets,  of  Bars  of  magnet- 
ized Soft  Iron,  and  of  Galvanic  Coils,  in 
their  Action  on  external  small  Magnets 
— with  Appendix  by  James  Stuart. 

1872  Feb.  12    Further  Observations  on  the  state  of  an     Camb.  Phil.  Soc. 
Eye  affected  with  a  peculiar  malforma- 
tion. 

1872  Mar.  20  Notes  on  Scientific  Education,  submitted 
to  the  Royal  Commission  on  Scientific 
Instruction  and  the  Advancement  of 
Science. 

1872  May  9     On   a   Supposed   Periodicity   in   the   Ele-     R.  Soc.     (Proc.) 
ments  of  Terrestrial  Magnetism,  with  a 
period  of  26^  days. 

1872  Nov.  30  Address  (as  President)  delivered  at  the 
Anniversary  Meeting  of  the  Royal  So- 
ciety. 


PRINTED    PAPERS   BY   G.   B.   AIRY. 


397 


Date  when  read 
or  published. 


Title  of  Paper. 


1872  Dec.  19  Magnetical  Observations  in  the  Britannia 

and  Conway  Tubular  Iron  Bridges. 

1873  Feb.  25    Remarks  on  Mr  Thornton's  Paper  on  "The 

State  Railways  of  India" — chiefly  in  refe- 
rence to  the  proposed  break  of  gauge. 

1873  Mar.  12  Note  on  the  want  of  Observations  of 
Eclipses  of  Jupiter's  First  Satellite  from 
1868  to  1872. 

1873  Mar.  14  Letter  to  the  Secretary  of  the  Admiralty 
on  certain  Articles  which  had  appeared 
in  the  Public  Newspapers  in  regard  to 
the  approaching  Transit  of  Venus. 

1873  Additional  Note  to  the  Paper  on  a  sup- 

posed Alteration  in  the  Amount  of  Astro- 
nomical Aberration  of  Light  produced 
by  the  passage  of  the  Light  through  a 
considerable  thickness  of  Refracting 
Medium. 

1873  Apr.  10  List  of  Candidates  for  election  into  the 
Royal  Society — classified. 

1873  On  tne  Topography  of  the  "  Lady  of  the 

Lake." 

1873  June  7  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1873  Nov.  14  On  the  rejection,  in  the  Lunar  Theory,  of 
the  term  of  Longitude  depending  for 
argument  on  eight  times  the  mean  longi- 
tude of  Venus  minus  thirteen  times  the 
mean  longitude  of  the  Earth,  introduced 
by  Prof.  Hansen  ;  &c. 

1873  Dec.  i     Address  (as  President)  delivered  at  the  Anni- 

versary Meeting  of  the  Royal  Society. 

1874  Jan.         On  a  Proposed  New  Method  of  treating 

the  Lunar  Theory. 
1874  May  4     British  Expeditions  for  the  Observation  of 

the  Transit  of  Venus,  1874,  December  8. 

Instructions  to  Observers. 
1874  June  6     Report  of  the  Astronomer  Royal  to  the 

Board  of  Visitors. 
1874  Aug.  6     Regulations    of   the    Royal    Observatory, 

Greenwich.     Appendix  to  the  Greenwich 

Observations,  1873. 
1874  Oct.  3      Science  and  Art.     The  Moon  as  carved  on 

Lee  church. 


Where  published. 
Phil.  Trans. 

Inst.  C.  E. 

(Minutes.) 

R.  Astr.  Soc. 
(Month.  Not.) 

R.  Astr.  Soc. 
(Month.  Not.) 


R.  Soc.     (Proc.) 


Private. 


R.  Astr.  Soc. 
(Month.  Not.) 


R.  Astr.  Soc. 
(Month.  Not.) 


Athenaeum. 


398 


APPENDIX. 


Date  when  read 
or  published. 


Title  of  Paper. 


1874  Nov.  13  Preparations  for  the  Observation  of  the 
Transit  of  Venus  1874,  December  8-9. 

1874  Nov.  17  Remarks  on  the  Paj$er  "On  the  Nagpur 
Waterworks." 

1874  Dec.         Telegrams  relating  to  the  Observations  of 

the  Transit  of  Venus  1874,  Dec.  9.   ^ 

1875  Feb.  2      Remarks  on  Mr  Prestwich's  Paper  on  the 

Origin  of  the  Chesil  Bank. 
1875  Feb-  2 5    Letter  to  the  Rev.  N.  M.  Ferrers,  on  the 

subject  of  the  Smith's  Prizes. 
1875  Mar.  12  On  the  Method  to  be  used  in  Reducing 

the  Observations  of  the  Transit  of  Venus 

1874,  Dec.  8. 

1875  Mar.  Report  on  the  Progress  made  in  the  Cal- 
culations for  a  New  Method  of  treating 

the  Lunar  Theory. 
1875  June  5     Report  of  the  Astronomer  Royal  to  the 

Board  of  Visitors. 
1875  June  7     Apparatus    for   Final  Adjustment  of   the 

Thermal  Compensation  of  Chronometers, 

by  the  Astronomer  Royal. 

1875  Nov.        Chart  of  the  Apparent  Path  of  Mars,  1877, 

with  neighbouring  Stars.  Also  Spectro- 
scopic  Observations  made  at  the  Royal 
Observatory,  Greenwich.  Also  Obser- 
vations of  the  Solar  Eclipse  of  1875, 
September  28-29,  made  at  the  Royal 
Observatory,  Greenwich. 

1876  Jan.          Report  by  the  Astronomer  Royal  on  the 

present  state  of  the  Calculations  in  his 
New  Lunar  Theory. 

1876  Jan.  27  Note  on  a  point  in  the  life  of  Sir  William 
Herschel. 

1876  Mar.  15  Evidence  given  before  the  Government 
Committee  on  the  Meteorological  Com- 
mittee. 

1876  May  20   On  Toasting  at  Public  Dinners. 

1876  June  3  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1876  Aug.  7     On  a  Speech  attributed  to  Nelson. 

1876  Dec.         Spectroscopic  Results  for  the  Rotation  of 

Jupiter  and  of  the  Sun,  obtained  at  the 
Royal  Observatory,  Greenwich. 

1877  Jan.         Stars  to  be  compared  in  R.A.  with  Mars, 


Where  published. 

R.  Astr.  Soc. 

(Month.  Not.) 
Inst.  C.  E. 

(Minutes.) 
R.  Astr.  Soc. 

(Month.  Not.) 
Inst.  C.  E. 

(Minutes.) 


R.  Astr.  Soc. 
(Month.  Not.) 

R.  Astr.  Soc. 
(Month.  Not.) 


Horolog.  Journ. 


R.  Astr.  Soc. 
(Month.  Not.) 


R.  Astr.  Soc. 
(Month.  Not.) 

Athenaeum. 


Public  Opinion. 


Athenaeum. 
R.  Astr.  Soc. 
(Month.  Not.) 

R.  Astr.  Soc. 


PRINTED   PAPERS   BY   G.    B.   AIRY. 


399 


Date  when  read 
or  published.  Title  of  Paper.  Where  published. 

1877,  for  Determination  of  the  Parallax        (Month.  Not) 
of  Mars. 
1877  Mar.        Note    by  the   Astronomer    Royal   on   the     R.  Astr.  Soc. 

Numerical  Lunar  Theory.  Also  Remarks         (Month.  Not.) 
on  Le  Verrier's  intra-Mercurial  Planet. 
Also  on  Observations  for  the  Parallax  of 
Mars. 
1877  Mar.  27  Remarks    on    a    Paper    on    "The    River     Inst.  C.  E. 

Thames."  (Minutes.) 

1877  Apr.         On  observing  for  Le  Verrier's  intra-Mer-     R.  Astr.  Soc. 

curial  Planet.     Also  on  the  Parallax  of        (Month.  Not.) 
Mars,  and  Mr  Gill's  proposed  expedition. 
1877  May         On  the  vulgar  notion  that  the  Sun  or  Moon     The  Observatory 

is  smallest  when  overhead.  (No.  2). 

1877  June  2     Report   of  the  Astronomer  Royal  to  the 

Board  of  Visitors. 

1877  July  16    Report  on  the  Telescopic  Observations  of     Ho.  of  Commons 
the  Transit  of  Venus  1874,  made  in  the         Parly.  Paper. 
Expedition  of  the  British  Government, 
and    on    the    Conclusion  derived   from 
those  Observations. 
1877  Sept.  13  On  Spurious  Discs  of  Stars  produced  by    The  Observatory 

oval  object-glasses.  (No.  7). 

1877  Sept.  24  Obituary  Notice  of  the  work  of  Le  Verrier     Daily  News. 

—died  Sept.  23,  1877. 

1877  Nov.  20  On  the  Value  of  the  Mean  Solar  Parallax     The  Observatory 
&c.  from  the  British  telescopic  Obscrva-        (No.  8). 
tions    of   the   Transit    of   Venus    1874. 
Also  Remarks  on  Prof.  Adams's  Lunar 
Theory. 
1877  Nov.        On  the  Inferences  for  the  Value  of  Mean     R.  Astr.  Soc. 

Solar  Parallax  &c.  from  the  Telescopic        (Month.  Not.) 
Observations   of  the  Transit  of  Venus 
1874,  which  were   made  in  the   British 
Expedition  for  the  Observation  of  that 
Transit. 

1877  Numerical    Lunar    Theory:    Appendix  to 

Greenwich    Astronomical    Observations 
1875. 

1877  Dec.  6     On  the  Tides  at  Malta.  Phil.  Trans. 

1878  Correspondence   with   Le   Verrier  on   his     The  Observatory 

Planetary  Tables  in  1876.  (No.  10). 

1878  On  the  Proposal  of  the  French  Committee     The  Observatory 

to  erect  a  Statue  to  Le  .Verrier.     Also        (No.  13). 


400 


APPENDIX. 


Date  when  read 
or  published.  Title  of  Paper.  Where  published. 

on  the  Observation  of  the  approaching 

Transit -of  Mercury. 

1878  Mar.  ii   On  the  Correction  of- the  Compass  in  Iron  Phil.  Mag. 

Ships  without  use  of  a  Fixed  Mark. 

1878  Mar.  30  On  the  Standards  of  Length  in  the  Guild-  The  Times. 

hall,  London. 

1878  Apr.  27    Report  of  Lecture  on  "The  probable  con-  W.  Cumberland 

dition  of  the  Interior  of  the  Earth."  Times. 

On  the  probable  condition  of  the  Interior  Trans,  of  the 

of  the  Earth— Revised  Edition  of  above  Cumberland 

Lecture.  Assoc.,  &c. 

1878  June  i      Discussion    of    the    Observations    of   the  The  Observatory 

Transit  of  Mercury  on  May  6.  (No.  14). 

1878                  Abstract  of  Lecture  delivered  at  Cocker-  The  Observatory 

mouth  on  "  The  Interior  of  the  Earth."  (No.  14). 
1878  June  i     Report  of  the  Astronomer  Royal  to   the 

Board  of  Visitors. 

1878  July  i      Remarks  on  the  measurement  of  the  pho-  The  Observatory 

tographs  taken  in  the  Transit  of  Venus  (No.  15). 

Observations. 

1878  July  13    On  the  Variable  Star  R.  Scuti:  distortion  The  Observatory 

in  the  Photo-heliograph.  (No.  16). 

1878                  Remarks  on  Mr  Gill's  Heliometric  Obser-  The  Observatory 

vations  of  Mars.  (No.  20). 

1878  Dec.        Note  on  a  Determination  of  the  Mass  of  R.  Astr.  Soc. 

Mars,  and  reference  to  his  own   deter-        (Month.  Not.) 
mination  in  1828.  Also  Note  on  the  Con- 
junction of  Mars  and  Saturn,  1879,  June  30. 

1879  Jan.  i      On   the    remarkable    conjunction    of   the     The  Observatory 

Planets    Mars    and    Saturn    which   will        (No.  21). 

occur  on  1879,  June  3°- 

1879  Feb.  15   On  the  names  "  Cabul"  and  "  Malek."  Athenaeum. 

1879  Feb.  25   On  Faggot  Votes  in  Cornwall  in  1828.  Athenaeum. 

1879  Mar.  13    Letter  on  the  Examination  Papers  for  the 

Smith's  Prizes. 

1879  Apr.  7      Drafts  of  Resolutions  proposed  concern- 
ing Sadler's  Notes  on  the  late  Admiral 

Smyth's  "  Cycle  of  Celestial  Objects." 
1879  June  i     Letter  to  Le  Verrier,  dated  1875,  Feb.  5,  in     The  Observatory 

support  of  the  Method  of  Least  Squares.        (No.  26). 
1879  June  l     Remarks  in  debate  on  Sadler's  "Notes"     The  Observatory 

above-mentioned.  (No.  26). 

1879  June  7     Report   of  the  Astronomer  Royal  to  the 

Board  of  Visitors. 


PRINTED   PAPERS   BY  G.   B.   AIRY. 


4OI 


Date  when  read 
or  published. 


Title  of  Paper. 


1879  Juty  29  Index  to  the  Records  of  occasional  Obser- 
vations and  Calculations  made  at  the 
Royal  Observatory,  Greenwich,  and  to 
other  miscellaneous  Papers  connected 
with  that  Institution. 

1879  Biography  of  G.  B.  Airy  (perhaps  corrected 

by  himself)  in  French,  published  at 
Geneva. 

1879  Sept.       On  the  Construction  and  Use  of  a  Scale 

for  Gauging  Cylindrical  Measures  of 
Capacity. 

1880  On  the  Theoretical  Value  of  the  Accelera- 

tion of  the  Moon's  Mean  Motion. 

1880  On  the  Secular  Acceleration  of  the  Moon 

— additional  note. 

1880  Apr.  27  Memoranda  for  the  Commission  appointed 
to  consider  the  Tay  Bridge  casualty. 

1880  Apr.  On  the  Theoretical  Value  of  the  Accele- 
ration of  the  Moon's  Mean  Motion  in 
Longitude  produced  by  the  Change  of 
Eccentricity  of  the  Earth's  Orbit. 

1880  May  On  the  Preparations  to  be  made  for  Obser- 
vation of  the  Transit  of  Venus  1882, 
Dec.  6. 

1880  On  the  present  Proximity  of  Jupiter  to  the 

Earth,  and  on  the  Intervals  of  Recur- 
rence of  the  same  Phenomena. 

1880  June  5  Report  of  the  Astronomer  Royal  to  the 
Board  of  Visitors. 

1880  Sept.  4    On  the  e  muet  in  French. 

1880  Sept.  4    Excursions  in  the  Keswick  District. 

1880  Dec.  i  Description  of  Flamsteed's  Equatoreal 
Sextant,  and  Remarks  on  Graham. 

1880  Addition  to   a   Paper    entitled   "On    the 

Theoretical  Value  of  the  Moon's  Mean 
Motion  in  Longitude,"  &c. 

1 88 1  Mar.        Effect  on  the  Moon's  Movement  in  Lati- 

tude, produced  by  the  slow  change  of 

Position  of  the  Plane  of  the  Ecliptic. 
1 88 1  June  4     Report  of  the  Astronomer  Royal  to  the 

Board  of  Visitors. 
1 88 1  Logarithms   of  the   Values   of  all  Vulgar 

Fractions  with  Numerator  and  Denomi- 

A.  B. 


Where  published. 

R.  Astr.  Soc. 

(Month.  Not. 
supplementary.) 


Phil.  Mag. 


The  Observatory 

(No.  37). 
The  Observatory 

(No.  37). 


R.  Astr.  Soc. 
(Month.  Not.) 


R.  Astr.  Soc. 
(Month.  Not.) 

The  Observatory 
(No.  42). 


Athenaeum. 
Keswick 

Guardian. 
The  Observatory 

(No.  44). 
R.  Astr.  Soc. 

(Month.  Not. 
supplementary. ) 
R.  Astr.  Soc. 

(Month.  Not.) 


Inst.  C.  E. 
(Minutes.) 

26 


402 


APPENDIX. 


Date  when  read 
or  published. 


Title  of  Paper. 


Where  published. 


nator  not  exceeding  100  :  arranged  in 
order  of  magnitude. 

1 88 1  July  6     A  New  Method  of  Clearing  the  Lunar  Dis- 
tance.— Admiralty. 

1 88 1  Aug.  4     On  a  Systematic  Interruption  in  the  order     Phil.  Mag. 

of  numerical  values  of  Vulgar  Fractions, 
when  arranged  in  a  series  of  consecutive 
magnitudes. 

1882  Sept.  15  Monthly     Means    of    the     Highest    and     R.  Soc.  (Proc. 

Lowest  Diurnal  Temperatures  of  the 
Water  of  the  Thames,  and  Comparison 
with  the  corresponding  Temperatures  of 
the  Air  at  the  Royal  Observatory,  Green- 
wich. 
1882  Oct.  19  On  the  Proposed  Forth  Bridge. 

1882  Dec.  7     On  the  Proposed  Forth  Bridge. 

1883  Jan.  21    On  the  Ossianic  Poems. 


1883  Mar.  12  On  the  proposed  Braithwaite  and  Butter- 
mere  Railway. 

1883  Apr.  28  Memorandum  on  the  progress  of  the  Nu- 
merical Lunar  Theory,  addressed  to  the 
Board  of  Visitors  of  the  Royal  Observa- 
tory, Greenwich. 

1883  Letter  on  The  Apparent  Inequality  in  the 

Mean  Motion  of  the  Moon. 

1883  Aug.  1 8  On  a  Singular  Morning  Dream. 

1883  Sept.  10  Power  of  organization  of  the  common 
mouse. 

1883  Nov.  17  On  Chepstow  Railway  Bridge,  with  general 

remarks  suggested  by  that  Structure. 

1884  Mar.  8     On  the  Erroneous  Usage  of  the  term  "  arte- 

rial drainage." 

1884  On  the  Comparison  of  Reversible  and  Non- 

reversible  Transit  Instruments. 

1884  Nov.  10  On  an  obscure  passage  in  the  Koran. 

1885  May  28   An  Incident  in  the  History  of  Trinity  Col- 

lege, Cambridge. 

1885  June  8  Incident  No.  2  in  the  History  of  Trinity 
College,  Cambridge. 

1885  Nov.  26  Results  deduced  from  the  Measure  of  Ter- 
restrial Magnetic  Force  in  the  Horizontal 
Plane,  at  the  Royal  Observatory,  Green- 
wich, from  1841  to  1876. 


Nature. 
Nature. 
Athenaeum. 

rDaily  News. 
J  Times. 

I  Standard. 


The  Observatory 

(No.  74)- 
Nature. 
Nature. 

Nature. 
Athenaeum. 

The  Observatory 

(No.  85). 
Nature.  (?) 
Athenaeum. 

Athenaeum. 
Phil.  Trans. 


PRINTED   PAPERS  BY  G.   B.   AIRY. 


403 


Date  when  read 
or  published. 


1886  Apr.  6 


Where  published. 
Nature. 


Title  of  Paper. 

Integer   Members  of  the  First  Centenary 

satisfying  the  Equation  A*  =  B*  +  C2. 
1887  Feb.  12  On  the  earlier  Tripos  of  the  University  of    Nature.  (?) 

Cambridge  :  in  MSS. 

1887  Apr.  14  On  the  Establishment  of  the  Roman  Domi- 
nion in  South-East  Britain. 

1887  July  23  On  a  special  Algebraic  function,  and  its 
application  to  the  solution  of  some  Equa- 
tions :  in  MSS. 


Nature. 


Camb.  Phil  Soc. 


26—2 


BOOKS   WRITTEN    BY   G.   B.   AIRY. 


Mathematical  Tracts  on  Physical  Astronomy,  the  Figure  of  the  Earth, 
Precession  and  Nutation,  and  The  Calculus  of  Variations.  This 
was  published  in  1826.  In  a  2nd  Edition  published  in  1831 
the  Undulatory  Theory  of  Optics  was  added  to  the  above  list. 
Four  Editions  of  this  work  have  been  published,  the  last  in  1858. 
The  Undulatory  Theory  of  Optics  was  published  separately  in 
1877. 

Gravitation :  an  Elementary  Explanation  of  the  Principal  Perturbations 
in  the  Solar  System.  Written  for  the  Penny  Cyclopaedia,  and 
published  previously  as  a  book  in  1834.  There  was  a  2nd  Edition 
in  1884. 

Trigonometry.  This  was  written  for  the  Encyclopaedia  Metropolitana 
about  1825,  and  was  published  as  a  separate  book  in  1855  under 
the  Title  of  "  A  Treatise  on  Trigonometry." 

Six  Lectures  on  Astronomy  delivered  at  the  meetings  of  the  friends  of 
the  Ipswich  Museum  at  the  Temperance  Hall,  Ipswich,  in  the 
month  of  March  1848.  These  Lectures  under  the  above  Title, 
and  that  of  "  Popular  Astronomy,  a  series  of  Lectures,"  have  run 
through  twelve  editions. 

On  the  Algebraical  and  Numerical  Theory  of  Errors  of  Observations 
and  the  Combination  of  Observations,  ist  Edition  in  1861,  2nd 
in  1875,  3rd  in  1879. 

Essays  on  the  Invasion  of  Britain  by  Julius  Caesar;  The  Invasion  of 
Britain  by  Plautius,  and  by  Claudius  Caesar;  The  Early  Military 
Policy  of  the  Romans  in  Britain;  The  Battle  of  Hastings;  with 
Correspondence.  Collected  and  printed  for  private  distribution  in 
1865. 

An  Elementary  Treatise  on  Partial  Differential  Equations.     1866. 

On  Sound  and  Atmospheric  Vibrations,  with  the  Mathematical  Elements 
of  Music.  The  ist  Edition  in  1868,  the  2nd  in  1871. 

A  Treatise  on  Magnetism,  published  in  1870. 

Notes  on  the  Earlier  Hebrew  Scriptures,  published  in  1876. 

Numerical  Lunar  Theory,  published  in  1886. 


INDEX. 


Accidents  (see  also  Illnesses)  125,  165, 

182,  281,  327 
Accounts  2,  361 — 363 
Acts  and  Opponencies  35,  38,  40 — 43 
Adams,  Prof.  J.  C.  116,  165,  169,  181, 
214,  216,  266,  274,  276,  337,  360, 
362 

Adams,  John  Quincey  139 
Agrarian  fires  92 
Aiken  151 
Airy,  William,  father  of  G.  B.  A.  14, 

15,  17,  19,  21,  34,  67,  71—74 
Airy,  Ann,  mother  of  G.  B.  A.  14,  15, 

50,  56,  67,  73,  8r,  91,  141,  148 
Airy,  William,  brother  of  G.  B.  A., 
and  Basil  R.  Airy,  his  son  15,  20, 
40,  60,  63—65,  67,  69,  74,  83,  103, 
105,  129,  137,  143,  149,  168,  172, 
249,  306,  358 

Airy,  Arthur,  brother  of  G.  B.  A.  15 
Airy,  Elizabeth,  sister  of  G.  B.  A.   15, 
24,  40,  50,  51,  64,  76,  81,  90,  91, 
137,  138,  141,  148,  327 
Airy,  Richarda,  wife  of  G.  B.  A.  56 — 
60,  71,  89,  90 — 92,  94,  96,  loo — 
103,  106 — 108,  in,  113,  119,  124, 
132,  137,  140,  141,  148,  151,  183, 
187,  205,  214,  225,  231,  242,  245, 
248,  253,  287,  293,  310 
Airy,  children  of  G.  B.  A. 
George  Richard  93,  140,  141 
Elizabeth  98,  207,  208,  212,  214 
Arthur  103,  140 
Wilfrid  129,  218,  225,  228,  231,  238, 

242,  245,  258,  272,  353 
Hubert  137,  225,  231,  238,  241,  242, 

248,  258,  261,  272,  288,  290,  296 
Hilda  143,  148,  242,  258,  272,  293 
Christabel  153,  272,  281,  288,  290, 

310,  318,  320,  347 
Annot  160,  253,  281,  293,  296,  310, 

318,  320,  347 
Osmund  172,  248,  253,  261,  263,  281, 

293,  323,  363 
Allsop  100 
Alnwick  14,  50,  272 
Altazimuth   instrument  158,   159,   165, 

195,  212,  228,  232,  236,  270,  301, 

333 

Althorp,  Lord  95,  100 

American  Observatories  139,  151,  263 


American  method  of  recording  Obser- 
vations (see  Galvanic  Registration) 

Ampere  69 

Ancient  eclipses  206,  213,  217,  229, 
230,  260 

Anderson,  lessee  of  Harton  Colliery 
220  • 

Anemometer  (see  Meteorology)  147, 
W  330,  334 

Anniversary  parties  310,  344,  366 

Antiquarian  researches  and  notes  207, 
220,  238,  320,  323,  359,  360,  361 

Arago  69,  97,  186 

Architecture  (see  Cathedrals,  &c.) 

Astronomical  Society  (see  Royal  Astr. 
Soc.) 

Astronomische  Gesellschaft  343 — 345, 

367 
Athenaeum  newspaper   179,  204,  217, 

219*  233>  234,  237,  240,  359 
Athenaeum  Club  62 
Atkinson,  Senior  Wrangler  1821,   30 
Atlantic  cable  230 
Atmospheric  railway  (see  Railways) 
Auckland,    Lord    104,    108,    109,    124, 

185 

Aurora  Borealis  294 
Australian  Observatories  (see  also  Ob- 
servatories) 204 
Auwers,  Dr  343—345 
Babbage,  Charles   24,  37,  48,  70,  92, 

152,  238 
Baily,  Francis  87,  91 — 93,  95,  98,  101 

—103,    125,    127,   130,    133,    134, 

139,  144,  158,  165,  172 
Bakhuysen,  of  Leyden  331 
Balance  (Public  Balance)  304 
Baldock,   Commander  213 
Baldrey,  assistant  87,  89,  114 
Banks,  optician  38 
Baring,  Sir  T.  no,  204,  206 
Barlow,  Prof.   79,  134,  171,  176 
Barlow,  W.  H.  303,  331 
Barnard,  Proctor  91 
Barnes,   Miss  138 
Barnes,  Gorell  264 
Barometers  291,  301,  304,  319 
Barry,  Sir  C.  217 
Barton,  Bernard  17 

Baxter,  secretary  to  the  Admiralty  290 
Beacons,  floating  230 


406 


INDEX. 


Beaufort,    Captain    93,    95 — 97,    IOT, 

102,  124,  125,  132—134,  138 
Beaumont's  Observatory  104 
Bedingfield,  pupil  29 
Bell  Scholarships  (see  Examinations) 
Bessell,  astronomer  76,  98,  99 
Biddell,  Arthur,  uncle  of  G.  B.  A.  16, 

i7»   *9,  23,  71,  9L  92»  IIO»    I29» 

132,  160,  242 
Biddell,  George,  uncle  of  G.  B.  A.  67, 

172,  208 

Biddell,  William,  uncle  of  G.  B.  A.  56 
Biddell,  George  Arthur,  son  of  Arthur 

Biddell  171—176,  180,  188 
Biographical  notes  295,  296 
Bissett,  pupil  50 
Blackwood,  Captain  206,  210 
Blakesley,  Canon  161 
Blasting  138,  146,  160,  163 
Bliss's  observations  157,  159 
Blomfield,  G.  B.,  pupil  32 
Bloomfield,  Lord  188,  190 
Board  of  Longitude   72 — 74,    76,    77, 

79—82,  85,  141,  231 
Boileau  27 
Bond,  G.  P.  230 

Books,  written  by  G.  B.  A.,  Appendix 
Book  Society,  Cambr.  55 
Bosanquet  206 
Bouch,  T.  Civ.  Eng.  303 
Boundary  of  Canada  (see  Canada) 
Bouvard,  E.  69,  76,  77,  134,  165 
Bowstead,  109 
Bradley's  observations   102,   157,    159, 

243 

Brazil,  Emperor  of  295,  298,  355 
Breakwaters  (see  Harbours) 
Breen,  assistant  157,  206 
Brewster,  Sir  D.  95,  96,  100 
Bridges  64,  77,  180,  185,  189,  197,228, 

271,  302,  3«>3»  33',  356 
Brinkley,  Dr  75 
Bristow,  Miss  149 
Britannia  Bridge  (see  Bridges) 
Brooke,  Charles  171,  179,  195 
British    Association    94 — 97,   99,    103, 

130,   143,  165,  169,  170,   187,  205, 

206,  213,  244,  247,  358 
Brougham,  Lord  101,  103 
Browne,  G.  A.  86 
Brunei,  Civ.  Eng.  175 
Buck  124 
Buckland,  Dr  91 
Buckle,  pupil  35,  36,  39,  40,  51 
Burgoyne,  Sir  J.  157 
Burlington,  Lord  131,  136,  187 
Burton  323 
Busts  (see  Portraits) 
Calculating  machines  37,  152,  230 
Calvert  60 

Cambridge  Observatory  : 
Assistants  87,  98 


Cambridge  Observatory : 

Instruments  84,  89,  90,  92,  94,  96 — 

98,  100,  104,  no,  114 — 116,  125, 

129,  132,  138,  151,  165 
Printed  observations  85,  87,  88 — 91, 

93'  96,  99»    Io8'    IIO>    "4— "6» 

i*5'  T32 
General   78 — 87,    90 — 94,    97,    103, 

108,  in,  114 — 116,  129,  216,  365 
Cambridge  University  227,    230,  232, 

237,  247,  251,  287,  332 
Cambridge  Observatory,  U.S.A.  271 
Canada  boundary  160,  167,  168 
Cankrein,  pupil  53,  72 
Canning,  Lord  160,  180 
Cape  of  Good  Hope,  Observatory  and 

Survey  95,  96,  101,  104,  131 — 133, 

140,  142,  153,  158,  201,  205,  206, 

219,  244,  252,  253,  288,  326,  332 
Carpenter,  assistant  302 
Cartmell,  Dr  266—269 
Case  144,  145 

Catalogues  of  stars  (see  Stars) 
Cathedrals  and  churches  50,  83,  145, 

147,  149,  155,  176,  210,  361,  362 
Catton  78 
Cavendish  experiment    130,    133,    139, 

148 

Cayley,  Prof.  273—280,  309,  327,  355 
Challis,   Prof.   34,   91,   138,    151,   165, 

169,  181 

Chalmers,  Dr  51 
Cherbourg  (see  Harbours) 
Chesil  Bank  155,  156 
Childers  27,  28 
Childers,  First  Lord  of  Admiralty  286, 

290 

Christchurch  154,  155 
Christie,  Prof.  126,  134,  185 
Christie,  Astronomer  Royal  288,  318, 

3^0,  335,  353'  360 
Chronographic    barrel    (see    Galvanic 

Registration) 
Chronometers  67,  68,  85,  in,  124,  127, 

i33»  ^S,  H1*  J53,  r58,  205,  219, 

244,  258,  259,  260,  270,  280,  289, 

302,  307*  313'  322,  335,  3^5 
Churches  (see  Cathedrals) 
Church  service  355,  356 
Cincinnati  Observatory  151 
Clarendon,  Lord  227 
Clark,  Latimer  217 
Clarkson,  Thomas,  and  Mrs  Clarkson 

17,  19—23,  31,  62,  64,  234,  313, 

327—329 

Cleasby,  pupil  64,  72 
Clegg  157 

Clinton,  pupil  50,  53,  64 
Clocks,   158,  180,    187,  201,  206,  207, 

213,  215 — 218,  220,  223,  226,240, 

270,  293,  3OI»  3°6,  32i,  324,  366 
Cockburn,  Sir  G.  178 


INDEX. 


407 


Coinage  (see  Decimal  Coinage) 
Colby,  Col.  91,  95,  140,  148,  152,  202, 

357 

Colchester  15 — 21,  141,  318,  362 

Colenso,  Bishop  264,  265,  310 

College  Hall  45—47 

Collorado,  Count  188 

Colonial  Observatories  (see  Observa- 
tories) 179 

Comets  83,  86,  95 — 97,  no,  133,  169, 
180,  195,  201,  204,  232,  307 

Commissions  133,  134,  139,  151,  158, 
165,  169,  171,  175,  176,  180,  196, 
217,  224,  228,  237,  240—242,  247, 
257,  280,  281,  287,  301,  331,  335 

Compass  corrections  134 — 136,  139, 
140,  165,  219,  224,  228,  237,  260, 
3r3»  3^0,  359,  363,  364 

Cookson,  Dr  282 — 284 

Cooper,  pupil  62,  63 

Cooper's  telescope  (see  Telescopes)  108 

Copying  press  123 

Corbaux,  Miss  204 

Corryvreckan  whirlpool  248 

Courtney,  Rev.  J.  92,  137,  148 

Cowper,  First  Commissioner  of  Works 
240 

Crawford,  pupil  76 

Criswick,  assistant  221,  246 

Cropley,  67,  69,  71,  73 

Crosse,  Rev.  E.  17,  19,  20 

Cubitt,  Sir  W.  17,  34,  56,  73,  no, 
163 

Daguerrotypes  144 

Dalhousie,  Lord  171 

Davy,  Sir  Humphrey  54,  55,  67 

Davy,  Dr  70,  80,  81,  100 

Daynou,  Lieut.  227 

Deal  time  ball  213,  216,  217,  218,  222, 
228,  231 

De  Berg  187 

Decimal  coinage  and  decimal  sub- 
dividing 204,  217,  224,  281 

Dee  navigation  (see  Rivers) 

Degrees  (see  also  Orders  and  Elections 
to  Societies)  40,  61,  69,  165,  195, 
196,  251,  272,  311 

Deighton,  publisher  67,  90 

De  La  Rive  233 

De  La  Rue  241,  295,  302,  348 

De  Launay  293,  296,  303 

Deluge,  The  220 

De  Morgan,  A.  227 

Denison,  E.  B.  180,  207,  213,  217 

Denison,  Sir  W.  133,  184 

Denison,  H.  207 

Denmark,  King  of  169,  195,  204 

Dent,  clockmaker  158 

Dent-dale  149,  150 

Devonshire,  Duke  of  251 

Dobbs,  pupil  6 1 — 63,  65,  69 

Dobree,  lecturer  27,  30 


Docks  (see  Harbours) 

Dolcoath  experiments  66 — 68,  71,  79, 

83,  84 

Dollond,  instrument  maker  71,  92,  330 
Drainage  196,  231,  366 
Drinkwater,  Bethune  27,  32 — 36,  38 — 

40,  50—52,  134 

Double-image  micrometer  139,  141,  330 
Douglas,  Sir  H.  228 
Dover  (see  Harbours) 
Dublin  professorship  (see  Professorships) 
Dublin  Observatory  (see  Observatories) 

108 

Due,  Baron  211 
Dundas,  Admiral  207 
Dundonald,  Lord  180,  183,  184 
Dunkin,  assistant  206,  210,  221,  243,246 
Dunlop,  astronomer  96 
Durham  observatory  139 
Earnshaw  79 
Earth  currents  239,  245,  260,  281,  285, 

^86,  333 

Eastons,  manufacturers  77 
Eclipses   (see    also   Ancient    Eclipses) 

104,  115,  127,  151,  154,  186,  206, 

208,  209,  227,  232,  241,  242,  244, 

271,  292,  333 

Edinburgh  Observatory  101,  230,  232 
Edmonston,  Dr  208 
Education  (see  University  Education) 
Egyptian  Astronomical  Tablets  224 
Elections    to   societies,   &c.    (see  also 

Degrees  and   Orders)  50,  62,  64, 

83,  89,  108,  127,  217,  297,  311 
Electricity,  atmospheric  165,  215,  319, 

324»  330 

Ellenborough,  Lord  178 
Ellis,  W.,  assistant  221,  224,  237,  304, 

308 

Elphinstone  52 
Encke  and  Encke's  Comet  83,  95 — 97, 

i33»  !83 

Encyclopaedia    Metro politana    63,   65, 

67,  69,  83,  89,  94,  142,  152,  166 
Engines  (see  Steam-engines) 
Equatoreal,  large  224,   227,  229,   231, 

236,  241,  243,  263,  287,  288,  292, 

304,  306,  307 
Estcourt,  Col.  167 
Evans,  lecturer  23,  32 
Examinations  72,  74,  79,   86,  89,  93, 

95,  98,  102,  105,  185,  237 
Exhibitions  and  prizes  24,   27,  31,  38, 

49>  313 

Exodus  of  the  Israelites  204 
Eye,   defects  of  61,  63,  65,  220,  237, 

244 

Eye,  estate  at  132,  143 — 145 
Fallows,  astronomer  95,  201 
Faraday  93,  95,  2 1 7,  244 
Farish  52 
Farr  230 


408 


INDEX. 


Fellowship  53,  61,  69 

Field  27,  38,  41,  61 

Fisher  39 

Fishmongers'  Company  24 

Fletcher,  Isaac,  M.P.  272,.  288,  323 

Floating  Island,  Derwentwater  320       ?' 

Fluid  telescope,  Barlow's  79 

Foley  39 

Forbes,  Prof.  J.  D.  126,  179,  196,  204 

Foster,  Messrs  189 

Fox,  Alfred  173 

Freedom  of  the  City  of  London  311 — 

3H 

Freemantle,  Sir  T.  204 

French,  Dr  70,  78 

Friends,  Personal  friends  at  Cam- 
bridge 116 — 122 

Fries,  Prof.  210 

Galbraith  84 

Galle  181,  183,  188 

Galvanic  communication,  Time-signals, 
Clocks,  and  Registration  (see  also 
Earth  currents)  201,  203,  204, 
206,  211,  213,  215 — 218,  222,  223, 
226,  228,  230,  231,  233,  240,  244, 
256,  258,  259,  262,  263,  280,  302, 
326,  331,  333 

Gambard  88 

Gas  Act  237 

Gauss  126,  139,  183 

Gautier  88,  233 

Geodesy  240,  323,  353 

Geology  55,  84,  91,  100,  353 

Geological  Society  89 

Germany  302 

Gibson,  pupil  32,  36,  39,  40,  52 

Gilbert,  Messrs  77 

Gilbert,  Davies  79,  87,  89,  96,  134 

Gill,  astronomer  318,  322,  326,  332 

Gladstone,  W.  E.  179,  217,  336 

Glaisher,  assistant  98,  104,  109 — nr, 
115,  129,  130,  132,  142,  148,  185, 
216,  304 

Glasgow  Observatory  139,  143 

Gordon  72 

Gosset  202 

Goulburn,  Chancellor  of  the  Exchequer 
151,  152,  162 

Gould,  Dr  B.  A.  271,  301,  343 

Goussel  62 

Graduation  of  circles  194 

Grant,  of  Glenmoriston  96 

Great  Circle  sailing  (see  Navigation) 

Great  Eastern  (see  Ships) 

Great  Exhibition  206,  207 

Great  Gable  148,  220 

Green,  Commander  U.S.N.  331 

Greenwich  187,  367 

Greenwich  Observatory,  before  his  ap- 
pointment as  Astronomer  Royal 
54,  55,  68,  76,  80,  82,  85,  88,  90, 
92—96,  99,  103 


Greenwich  Observatory: 

Appointment  as  Astronomer  Royal, 
and  subsequently  as  Visitor  103 — 
105,  108,  109,  222,  306,  335—337, 
339,  340,  346,  354 

Buildings  and  grounds  in,  123,  124, 
126,  131,  133,  139,  168,  194,  200, 
205,  216,  224,  242,  245,  259,  262, 
269,  280,  285,  315,  321,  329 

Instruments  j 30,  133,  139,  157— 159, 
180,  182,  184,  185,  194,  205,  214, 
215,  218,  224,  226,  229,  231,  238, 
240,  243,  257,  259,  262,  269,  270, 
287,  286,  288,  291,  293,  301,  302, 
304,  306,  315,  318,  320,  321,  331, 

333,  353 
Assistants    109,  129,  130,  157,   201, 

21-6,  238,  290,  296,  304,  341,  342, 

367,  368 

Computations  244,  280 
Papers    and    manuscripts    (arrange- 
ment of)  123,  131,  158,  1 68,  179, 

280,  324 

Estimates  151,  178,  269,  290,  326 
Printed  Observations  138,  152,  153, 

157,  165,  195,  218,  263,  319,  324, 

326,  363 
Visitations   and    Reports    125,    141, 

i53>  157,  !59>  l6°,  l8l>  J82,  184, 
185,  203,  205,  212,  215,  216,  224, 

226,  231,  232,  236,  240,  246—248, 
258,  262,  271,  289,  290,  293,  295, 

303,  3°9,  326,  335,  337—339»  35°", 

360,  362,  363,  365 
General    132,    141,    160,    179,    240, 

310,  360 
Gresswell  224 

Groombridge's  Catalogue  (see  Stars) 
Guest,  Caius  College  52,  61,  108,  188 
Haarlem  211 
Hall,  Col.  202 

Halley  and  Halley's  Comet  1 10, 2 19, 29 1 
Hamilton  38,  41,  207 
Hamilton,  Sir  W.  R.  75,  196 
Hamilton,  Admiral  240 
Hansard  76 
Hansen,  Prof.  181 — 183,  185,  204,  219, 

227,  229,  235,  236,  238,  239,  244 
Hansteen  206 

Harbours  169,  170,  176,  177,  217,  228 
Harcourt,  Rev.  W.  Vernon  94,  97,  no, 

175,  *7<5 

Hartnup,  astronomer  129,  130,  365 
Harton  Colliery  experiments  220,  221, 

223 

Haviland,  Dr  8,  148,  162 
Hawkes,  Trinity  College  40 
Hebrew  Scriptures  204,  220,  309,  358 
Heliograph  302 
Hencke  168 

Henderson,  astronomer  96,  101,  131 
Henslow,  Prof.  91 


INDEX. 


409 


Herbert,  G.  230 

Hereford  15,  225,  320 

Herschel,  Sir  John  24,  38,  48,  54,  55, 
67,  69,  74,  75,  82,  85,  89,  91,  93, 
94,  99,  100,  101,  114,  116,  132, 
140,  142,  153,  160,  163,  207,  220, 
221,  223,  233,  244,  297 

Herschel,  Miss  Caroline  183 

Herschel,  Col.  J.  359 

Hervey,  pupil  53 

Higman,  Tutor,  Trinity  College  39, 
53,  61,  62,  70 

Hilgard,  U.S.A.  301 

Himalaya  Expedition  (see  Eclipses) 

Hind,  Moderator  39 

Hind,  Superintendent  Nautical  Al- 
manac 142,  180,  201,  210,  212, 
216,  244 

Hopkins  109 

Hovenden,  pupil  63 

Hudson  175 

Huggins,  Dr  316,  344,  363 

Humboldt,  Baron  A.  jt^6j  188 

Humphreys  206,  209,  210 

Hussey,  Dr  134 

Hustler,  Tutor,  Trinity  College  21,  22, 
24,  25,  27,  28,  33,  41 

Hyde  Parker,  Admiral  183 

Hygrometers  103 

Ibbotson,  pupil  69 

Iliff  27 

Illnesses  101,  129,  173,  182,  183,  327, 
353.  360,  362—367 

Inequality,  Venus  and  Earth  77,  78, 
94,  98,  99 

Inglis,  Sir  R.  179 

Institut  de  France  104,  105,  297 

Institution  of  Civil  Engineers  152,  207, 
271 

Inverness,  Northern  Institution  of  64 

Ipswich  Lectures  195 — 197,  362 

Ireland,  notes  of  163,  164 

Ivory  75 

Jackson  83 

Jackson,  John  360 

James,  Sir  H.  220,  240 

Janus  (see  Steam-engines) 

Jarrow  (see  Harbours) 

Jeffries  38—40 

Jerrard,  Dr  136 

Jervis,  Major  140 

Jeune,  Dr,  V.  C.  of  Oxford  243 

Johnson,  Capt.  134 

Johnson,  astronomer  238 

Jones,  instrument-makers    77,    83,    84, 

94,  96,  97 

Jones,  R.  09 

Journeys : 

Scotland  and  Cumberland  50;  Swan- 
sea 52 ;  Derbyshire,  &c.  60 ;  Wales 
64;  Keswick,  &c.  64;  Cornwall, 
&c.  67,  68 ;  Orleans  69 ;  Lake 


District,  &c.  76;  Continent,  Ob- 
servatories, &c.  88 ;  Cornwall,  &c. 
83,  84;  Derbyshire  90;  Oxford 
&c.  91;  Cumberland  91  ;  Ireland 
94;  Scotland  96;  Derbyshire,  &c. 
100;  Cumberland,  &c.  103;  Ire- 
land 1 08;  Kent  129;  S.  Wales 
132;  Luddington  and  Yorkshire 
137 ;  Border  of  Scotland  143 ; 
S.  Wales  148 ;  Cumberland  and 
Yorkshire  148 — 150;  South  of  Ire- 
land 1 60 ;  Ireland  168 ;  France 
172;  Cornwall  172;  Germany  183; 
Petersburg,  &c.  188;  Ireland  196; 
Shetland  202  ;  Scotland  205  ; 
Sweden  208 — 211;  Madeira  214; 
Cumberland  217 ;  Cumberland 
221;  Oban,  &c.  225;  Italy  and 
Sicily  228;  West  Highlands  231; 
Switzerland  233;  Central  France 
238 ;  Spain  (eclipse)  242 ;  Cumber- 
land 245 ;  West  Highlands  248 ; 
West  Highlands  253;  Cumberland 
261 ;  Norway  263  ;  Cumberland 
272;  Switzerland  281;  Cumber- 
land 288  ;  Cumberland  290 ;  Cum- 
berland 293;  Scotland  296;  Scot- 
land 306;  N.  of  Scotland  318; 
Ireland  320;  Scotland,  &c.  324; 
Cumberland  327 ;  Cumberland 
332;  Cumberland  350;  Cumber- 
land 352;  S.  Wales  354;  Cum- 
berland 358;  Cumberland  362 

Julius  Caesar,  landing  of  207 

Jupiter  (see  Planets)  97,  99,  104,  115, 
116,  127,  307,  319 

Keeling  18 

Kennedy  90 

King,  Joshua  70,  78 

Kingstown  253 

Knight,  publisher  103 

Knighthood,  offers  of   in — 113,    187, 
254—256,  296 

Lagarde  69,  88 

Laing  171 

Landman,  engineer  126 

Langton  272,  288,  290,  293,  296,  306 

Laplace  69,  79,  99 

Lardner,  Dr  75 

Lassell,   and    Lassell's    telescope    195, 
196 

Latitude  determinations  83,  114 

Lax,  Prof.  40,  72,  85,  87 

Lectures : 

College  62,  65—67,  70 
Professorial  71 — 77,  So,  87,  90,  93,  96, 
99,  102,  104,  108,   113,  114,  124, 
125 

Miscellaneous  70,  132,  142,  169,  195, 
196,  206,  207,  217,  230,  233,  244, 
260,  287,  323,  362,  367 

Lefevre,  J.  G.  S.  134,  171 


INDEX. 


Leitch,  Dr  220 

Le  Verrier  181,  187,  233,  257,  317 

Lewis,  H.  52 

Lewis,  Sir  G.  C.  224,  254 

Lightfoot,  Rev.  Dr  285 

Lighthouses  51,  225,  240 — 242,  355 

Lightning  262 

Lillingstone  96 

Lindsay,  Lord  326 

Listing,  Prof.  343,  353 

Liverpool  Observatory  139,  151,  179, 
196,  201,  253,  365 

Livingstone,  Dr  230 

Lloyd,  Dr  75 

Lloyd,  Prof.  1 26 

Lockyer  362 

Lodge  83,  88 

London  University  131,  136,  139,  148, 
1 80,  1 86 

London,  Freedom  of  the  City  311 — 314 

Long  vacations,  with  pupils  52,  64,  69 

Longitude  determinations  85,  91,  93, 
158,  160,  166—168,  216,  219,  223, 
227,  230,  232,  240,  246,  253,  263, 
271,  301,  319,  325,  331,  332 

Longitude,  Board  of  (see  Board  of  Longi- 
tude) 

Lowe,  Chancellor  of  the  Exchequer  220 

Lubbock,  Sir  John  98,  99, 127, 130,  131, 
134,  136,  142,  238 

Lucas  (computer)  233 

Lucasian  Professorship  (see  Professor- 
ships) 

Lunar  Reductions  127,  130,  133,  139, 
142,  148,  151,  153,  158,  165,  181, 
185,  195,  214,  235,  239 

Lunar  Theory  and  Tables  (see  also 
Numerical  Lunar  Theory)  127,  131, 
185,  204,  227,  229,  235,  236,  239, 

244»  313.  354>  36o 

Lyndhurst,  Lord  105,  162,  168,  171 

Lyons,  Sir  E.  209 — 211 

Macaulay,  T.  B.  61 

Macdonnell,  Dr  75 

Maclean,  of  Loch  Buy  96 

Maclear,  Astronomer  92,  93,  101,  131, 
133'  r58»  2I9»  238,  244.  253 

Madras  Observatory  101 

Magnetic  Observatory  and  Magnetism 
(see  also  Meteorology,  Compass 
corrections,  and  Earth  currents  124, 
126,  131,  133,  139,  141,  142,  148, 
151,  165,  169,  170,  171,  179,  185, 
I95>  2«>3.  215,  216,  222,  224,  233, 
239,  240,  244—248,  252,  256,  257, 
259,  260,  263,  281,  287,  291,  292, 
294,  302,  304,  319,  325,  326,  330, 

334,  357.  358 

Main,  Robert  109,  no,  216,  238 
Maine  Boundary  (see  Canada) 
Maiden,  Prof.  207,  220 
Malkin  27,  52,  63 


Malta  320 

Man-Engines  (see  Mines) 

Manuscripts  (see  Papers) 

Mars  (see  Planets)  116,  252,  318 

Marshman,  pupil  64,  65 

Marth,  A.  240 

Martin,  Trin.  Coll.  161 

Maskelyne,  astronomer  102,  128,  159 

Mason  39 

Mathematical  Investigations    (see  also 

Appendix  "Printed  Papers")  224, 

240,  247,  355,  357 
Mathematical  Tracts  65 — 67,   90,   94, 

233 

Mathematical  subjects  in  1819,  47,  48 
Maudslays  and  Field  218 
May,  Ransomes  and  May  158,  194 
Medals  95,  98,  104,  169,  180,  193,  272, 

320 

Melbourne  University  220 
Melville,  Lord  87 
Mercury  (see  Planets)  286 
Merivale,  Dr  327,  328 
Meteorology   116,  147,   168,  179,  232, 

270,  271,  281,  289,  291,  292,  301, 

303,  304,  3l6«  3!9>  322,  324,  326, 

330,  33L  334,  355—357 
Meteors  270 
Middleton,  Sir  W.  207 
Milaud  209,  210 
Military  researches  238 
Miller,  Prof.  102,  158,  237 
Mines  66,  67,  71,  76,  79,  83,  84,  172— 

175,  189 

Minto,  Lord  124,  135,  i  f2 
Mitchell,  astronomer  151,  203 
Mitchell  Miss  195 
Molesworth,  Sir  W.  217 
Monteagle,  Lore}  237 
Monument  in  Playford  church  137 
Moon: 

Observations  of  158 — 160,  195,  214, 

230,  235,  263,  307,  316,  324 
Theory   and   Tables   of  (see   Lunar 

Theory  and  Tables) 
Reductions  of  Observations  of  (see 

Lunar  Reductions) 
Mass  of  88,  89 
Morpeth,  Lord  196 
Morton,  Pierce,  pupil  52,  108,  205 
Murchison,  Sir  R.  213 
Murray,  publisher  176 
Musgrave,  Charles  21,  22,  34 
Musgrave,  T.  Archbishop  21,  22,  85 
Myers  27,  31,  33,  39,  265 
Nasmyth  169 
Nautical  Almanac  74,  76,  77,  85,  87, 

91,  92,  104,  214,  216,  331 
Navigation  233,  313,  365 
Neate,  pupil  53 
Neptune  and  Uranus  133,  134,  165,  169, 

181,  183,  186 


INDEX. 


411 


Newall  306,  318 

Newcombe,  Prof.  343 

New  Forest  155 

Northampton,  Lord  142,  144 

Northumberland  Telescope  100,  104, 
no,  125,  132,  138,  151,  165 

Numerical  Lunar  Theory  293,  296,  303, 
305,  308,  317*  3J9»  32<>»  323.  325, 
335,  346—350.  354»  356, 358,  360— 
362 

Observatories:  see 

American,  Australian,  Beaumont's, 
Cambridge,  Cambridge  U.S.A., 
Cape  of  Good  Hope,  Cincin- 
nati, Colonial,  Dublin,  Durham, 
Edinburgh,  Glasgow,  Greenwich, 
Liverpool,  Madras,  Oxford,  Paris, 
Paramatta,  Pulkowa,  St  Helena, 
Williamstown 

Occultations  227 

O'Connell  163,  164 

Ogilby,  pupil  65,  69 

Oppolzer,  Prof.  325 

Opponencies  (see  Acts  and  Opponencies) 

Optics  55,  75— 77,  87,  90,  92,  93,  95, 
in,  220,  323,  336,  363 

Orders  (see  also  Degrees  and  Elections 
to  Societies)  187,  191 — 193,  220, 
256,  293,  296,  298,  304,  311 

OuvarofT,  Count  188,  191 — 193 

Oxford  Observatory  142 

Oxford,  Miscellaneous  165 

Packington,  Sir  J.  233 

Palmerston,  Lord  256 

Papers  (see  Appendix  "  Printed  Papers") 

Papers,  Arrangement  of  123,  131,  158, 
168,  179,  280 

Parachute,  Fall  of  1 30 

Parallax  (see  Sun) 

Paramatta  Observatory  96,  179 

Parker,  Charles  1 1 1  » 

Parker,  Vice-Chancellor  49 — 52 

Paris,  Dr  66,  67 

Paris  Observatory  223,  257,  269,  290, 


291,  301 
s  Exhibition,  222 


Paris 

Parliamentary  Elections  98,  104,  130 

Pasley,  Col.  146 

Paul  142 

Peacock,  George  22,  23,  25,  26,  28,  31 — 

33,  35,  38>  40,  45,  48,  49»  53,  55, 
63,  66,  69,  70,  77,  119—121,  134, 
152,  154,  161,  165,  182 

Pearson,  Dr  85 

Peel,  Sir  Robert  105 — 108,  151,  179 

Pendulum  Investigations  and  Experi- 
ments 66,  67,  71,  79,  83,  84,  220, 
221,  223,359 

Penny  Cyclopaedia  97,  101,  132 

Pension  105 — 108,  306 

Pentland  104,  105 

Percy,  Bishop  218 


Personal  sketch  i — 13 

Philosophical    Society,   Cambridge  35, 

38,  50,  55,  63,  65,  70,  75,  85,  89, 

92,  93,  95,  99,  101,  104 
Philpott,  Dr  233 
Photography  230,  239,   241,  247,  295, 

302,  305,  307,  308,  316-319,  323, 

3*4,  33i 

Piers  (see  Harbours) 

Pinheiro,  Lieut.  355 

Pipon,  Lieut.  160 

Plana,  astronomer  88 

Planetary  influences  249,  250 

Planetary  Reductions  98,  100,  102,  104, 
no,  130,  133,  139,  142,  148,  153, 
180,  263 

Planets  (see  also  Transits  of  Venus)  77, 
78,  82,  94,  97—99,  104,  115,  116, 
127,  133,  134,  165,  168,  169,  181, 
183,  186,  195,  198,  200,  2or,  212, 
247,  252,  257,  263,  286,  291,  307, 
315,  318,  319,  322,  324 

Plantamour  234 

Playford  182,  320,  353,  and  frequently 
throughout 

Plumian  Professorship  (see  Professor- 
ships) 

Pocket-books  for  Observations  116 

Pogson,  astronomer  221 

Pond,   astronomer   73,  76,  80,  82,   87, 


93,  123,  127—129 
dock,  Capt.  95 


Portlock, 

Portraits,  busts,  &c.  50,  102,  354 

Post  Office,  (clocks,  &c.)  223,  226,  331, 

Post  Office,  stamps  and  envelopes  144 

Pouillet  69 

Prince  Albert  162,  207 

Pritchard,  Rev.  C.  215,  358,  362 

Prizes  (see  Exhibitions) 

Probable  errors  240 

Professorships : 

Dublin  75  ;    Lucasian  69 — 71 ;    Plu- 

mian  77 — 81,  86,  89,  92,  93,  no 
Public  Schools  Commission  247 
Pulkowa   Observatory  188 — 193,    252, 

Pupils : 

Bedingfield  29;  Bissett  50;  Blom- 
field  32  ;  Buckle  35,  36,  39,  40,  51; 
Cankrein  53,  72;  Cleasby  64,  72; 
Clinton  50,  53,  64 ;  Cooper  62 ; 
Crawford  76;  Dobbs  61 — 63,  65, 
69;  Gibson  32,  36,  39,  40,  52; 
Guest  52,  61,  108;  Hervey  53; 
Hovenden  63  ;  Ibbotson  69;  Lewis 
52;  Marshman  64,  65  ;  Morton  52, 
108,  205;  Neate  53;  Ogilby  65, 
69 ;  Parker  49 — 52  ;  Rosser  29,  30, 
32;  Smith  64;  Tinkler  69;  Tot- 
tenham 64;  Turner  53,  61 — 63, 
72,73;  Wigram64;  Williamson  49 


412 


INDEX. 


Pym,  Engineer  157 

Queen,  H.  M.  the  Queen,  161,  317 

Queroualle,  Mdlle  de  360 

Quetelet  88 

Railways,  near  Observatory  126,   178,  ^ 

252,  259,  262,  291,  294 
Railway  Gauge  Commission  171,  175, 

176,  180 
Railways,  miscellaneous  138,  143,  156, 

.  i57t  ^L  354 
Rain  (see  Meteorology) 
Rainbows  357 
Ransomes,  also  Ransomes  and  May  17, 

19,  20,  125,  152,  158,  194,  205 
Reach  50,  51 

Reflex  zenith  tube  194,  226 
Religious  tests  and  views  7,  264,  265, 

284,  285,  309 
Repsold  1 88 
Rhodes  131 

Richardson,  assistant  98 
Rigaud,  Prof.  87,  96,  102 
Rivers  207,  213,  217,  232,  334 
Robinson,  Dr  91,  94 
Robinson,  Capt.  160 
Rogers,  Rev.  21 
Rogers,  school  assistant  20,  56 
Romilly,  Lord  27,  28 
Ronalds  179,  195 
Rose,  Rev.  H.  J.  142 
Rosse,  Lord,  and  Rosse's  Telescope  161, 

179,    196,    198 2OO,   221,    222 

Rosser,  pupil  29,  32 

Rothery  351 

Rothman  36,  37,  40 

Round  Down  Cliff,  blasting  of  163 

Rouse,  Rev.  R.  C   M.  357 

Routh,  Dr  E.  J.  143,  244,  258,  266, 
272,  293 

Royal  Astronomical  Society  (see  also 
Appendix  "Printed  Papers")  83, 
89,  98,  99,  104,  127,  134,  169,  180, 
181,  186,  201,  202,  204,  206,  213, 
217,  219,  230,  272,  281,  305,  310, 
326,  348,  355 

Royal  Exchange  clock  158 

Royal  Institution  206,  217 

Royal  Society  (see  also  Appendix 
"  Printed  Papers ")  67,  73,  78,  83, 
92,  94,  95,  103,  127,  142,  148,  169, 
195,  202,  204,  213,  224,  230,  233, 
244,  247,  258,  272,  293,  303,  310, 

359 

Royal  Society  of  Edinburgh  108 
Runcker,  Paramatta  54 
Riincker  188,  220,  221 
Rundell  237,  363 
Rusby  38,  41 

Russell,  Lord  John  in,  191,  192 
Sabine,  Col.  223,  233,  240,  247,  248 
Sadler,  H.  326 
Saint  Helena  Observatory  127 


Samuda  157 

Saturn  (see  Planets)  82,  307 

Saunders,  G.  W.  Ry  175 

Saw-mills  (see  Ship  timbers) 

Schehallien,  mountain  204 

Scholarship  35,  36 

Scholefield  162 

Schumacher  91,    134,    169,   180,   188, 

195,  201,  214 
Scientific  Manual  185 
Scoop- wheels  152 
Scoresby,  Dr  219,  237 
Scriptural     Researches    (see     Hebrew 

Scriptures) 
Sedgwick,  Adam  22,  54,  69,  72,  83,  84, 

98,  100,  119,  136,  140,  149,  153, 
161,  173,  182,  187,  299,  300 

Selvvyn,  Prof.  264 

Senate    House   Examination    (see   also 

University  Education)  39,  43 — 45, 

237,  265,  266,  273,  282 — 284 
Sewers  Commission  196 
Sheepshanks,  Rev.  Richard,  and  Miss 

Sheepshanks  67,  77,  78,  80 — 85, 

92>  93'  95'  97»  98>  100—105,  108, 

in,  114,  121,  130,  134,  142,  165, 

202,  224,  227,  230,  301 
Sheepshanks  Fund  and  Scholarship  227, 

230,  232,  237,  247,  365 
Shepherd,  clock-maker  206,  213,  223 
Ships  231,  237,  260,  351 
Ship-timbers,    Machinery    for    sawing, 

152,  169,  187 
Shirreff,  Capt.  152,  183 
Simmons  221 
Simms,  F.  W.  109 
Simms  (see  Troughton  and  Simms) 
Skeleton  forms  37,  102,  no,  123,  148, 

1 60 

Sly,  draughtsman  151 
Smith,  Rev.  R.  Smith,  father-in-law  of 

G.  B.  A.,  and  Mrs  Smith,  56—60, 

66,  71,  132,    137,    142,    187,  231, 

238 
Smith,   the    Misses    Smith,   sisters    of 

Richarda  Airy,  Susanna  91,  101 ; 

Elizabeth  99,  in,  183;  Georgiana 

99,  103,  in,  172;  Florence,  108; 
Caroline  138 

Smith,  Archibald  237 

Smith,  Sir  Frederick  171,  175 

Smith,  M.,  pupil  64 

Smith,  engineer  156 

Smith's  Prizes  40,  49,  72,  79,  86,  89, 
93>  95»  98,  102,  105,  230,  238,  260, 
309,  327 

Smyth,  Capt.  W.  H.  88,  91,  93,  157, 
167,  326,  330 

Smyth,  Piazzi  227,  230 

Societies,  &c.,  Elections  to  (see  Elec- 
tions) 

Solar  Eclipses  (see  Eclipses) 


INDEX. 


413 


Solar  Inequality  (see  Sun) 

Solar  System  (see  Sun)  253 

Solar  Tables  (see  Sun) 

South,  Sir  James  38,  54,  55,  69,  73,  87, 

91—93,96—99,  103,  157,  179,  185, 

238 

South's  Telescope  97—99,  103 
South- Eastern  Railway  126,  179,   201, 

203,  206,  218,  233,  262,  294 
Southampton  154 
Southey  (Poet)  64,  65,  76,  149 
Spectroscopy  257,  304,  307,  315,  316, 

3i8,  330,  334 
Spottiswoode  355 
Spring-Rice,  Lord  Monteagle  104,  105, 

no — 112,  126,  130,  134,  136 
Standards  of  Length  and  Weight,  and 

Standards   Commission   133,    134, 

139,  *5'5  i58>  J65>  169,  217,  224, 

247,  257,  280,  281,  287,  301,  313 
Stars  97,  100 — 102,  no,  127,  130,  132, 

i33>  l65>  20I»  23°»  253»  28°">  289> 
304,  307,  322,  324,  330,  357,  362 
Start  Point   230,   233,    244,   246,  258, 

309 
Steam-engines    18,    09,    70,    180,  183, 

184,  2ii 

Stephenson,  George  90 
Stephenson,  Robert  90,  178,  180,  204 
Steventon  109 
Stewart,  Prof.  Balfour  357 
Stjerneld,  Baron  209,  210,  211 
Stokes,  Prof.  274,  276,  305,  337,  366 
Stone,  Astronomer  238,  259,  280,  288, 

289,  291,  354 

Stratford,  Lieut.  93,  101,  156,  216 
Stroganoff,  Count  188 
Strutt,  Lord  Helper  27,  28 
Strutt,  Jedediah  60 
Struve,  Otto  165,  166,  188,  204,  205, 

240,  243,  343,  357 
Stuart,  Prof.  J.  350 
Sun: 

Miscellaneous  227,  253,  304,  307,  316, 

318,  320,  324,  325,  326,  331,  334 
Parallax    of    (see    also    Transits    of 

Venus)  230,  252,  318,  322,  323 
Eclipses  of  (see  Eclipses) 
Inequality,  Venus  and  Earth  77,  78, 


94,  98,  99 
able 


Tables  of  73,  76,  78 
Surveys  (see  Trigonometrical  Surveys) 
Sussex,  Duke  of,  103 — 105,  126 
Sutcliffe  36 
Sutcliffe,  Miss  148 
Sydney  University  207 
Sylvester  169,  187 
Sweden,  King  of  209,  210,  304 
Tate  27,  28 
Taylor,  architect  in 
Taylor,  First  Assistant  to   Pond,   100, 
124 


Taylor,  H.  97,  100,  101,  102,  127 
Telegraphs    (see    Galvanic    communi- 
cations) 

Telescopes  (see  also  Cambridge  Obser- 
vatory Instruments,  and  Greenwich 
Observatory  Instruments)  79,  97, 
98,  99,  103,  108,  196,  198—200, 
221,  230,  240,  286,  291,  292,  294, 
306 

Teneriffe  Experiment  227,  230 
Thames,  the  River,  232,  334 
Theology  (see  also  Hebrew  Scriptures 

and  Colenso)  356,  358,  363,  365 
Thermometers  179,  289,  301,  304,  316 
Thermo-multiplier  286,  288,  289 
Thirl  wall,  Bishop  272 
Thomas,  assistant  130 
Thompson,  Master  Trin.  Coll.  272 
Thomson,  Sir  W.  319,  359,  364 
Tidal  Harbour  Commission  169 
Tides,   142,   148,    152,    154,  165,   169, 

207,  213,  217,  240,  320 
Time-signals  and  Time  (see  also  Gal- 
vanic   communication,    &c.)    201, 
213,  215,  216,  222,  228,  230,  233, 
244,  258,  302,  309,  351,  352,  360, 

367 

Time  balls  (see  Time  signals) 

Tinkler,  pupil  69 

Tottenham,  pupil  64 

Traill,  Dr  60,  90 

Transit  Circle,  8-inch  185,  194,  205, 
2ii,  214,  216,  222,  229,  232,  238, 
243,  257,  262,  263,  269,  288,  291, 
315,  321,  324,  353 

Transits  of  Venus  261,  281,  286,  289, 
292,  295,  302,  304,  305,  308,  313, 
317,  318,  319,  322,  324,  325,  331, 

335,  346,  35° 
Trigonometrical   Survey  85,   95,    127, 

i32»  !33>  r40»  J42>  H8*  2°2»  «°f 

253,  269 
Trinity  College,  Cambridge   183,  227, 

233»  234,  247,  272,  285,  311,  356, 

365,  3^8 

Trinity  House  230 
Tripos  Examination  (see  Senate-House 

Examination) 
Troughton  and  Simms  94,  97,  98,  103, 

no,  132,  194,  205,  260,  286,  294, 

302.  315 

Tulley,  optician  38,  54,  90,  no 
Tupman,  Capt.  302,  323 
Turner,  pupil  53,  61—63,  72,  73 
Turton,  Prof.  40,  65,  90 
Tutorship  53,  61,  62,  65—67,  70 
Ulrich,  J.  G.  158 
Universities  (see   Cambridge,   Dublin, 

Edinburgh,    London,    Melbourne, 

Oxford,  Sydney) 
University  Education  (see  also  Smith's 

Prizes  and  Senate-House  Examina- 


414 


INDEX. 


tion)  39,  43—45,  47»  48>  I^'2,  265, 
266—269,     273—280,     282—284, 

3°9»  3^7,  33^,  361 

University  Press,  65,  85,  90,  95,  102 

Uranus  (see  Neptune) 

Valencia   (see  also    Longitude    Deter- 
minations) 158,  160,  240,  246,  253,- 
263,  271 

Venus    (see    Planets,   and  Transits  of 
Venus) 

Venus  and  Earth  inequality  (see  Ine- 
quality) 

Vernon  Harcourt  (see  Harcourt) 

Vetch,  Capt.  204 

Vibrations  of  ground    126,    178,  226, 
259,  291 

Vignoles,  C.  B.,  engineer  156,  241,  242 

Vulliamy,  clockmaker  187,  217 

Wales,  Prince  of  320 

Walker,  Byatt  15 

Walker,  James,  engineer  126 

Walker,  Sydney,  30 

Warburton,  H.  127,  187 

Washington,  Capt.  230 

Water   telescope   (see  also  Fluid  tele- 
scope) 240,  286,  291,  294 

Watson  175 

Waves  (see  Tides) 

Webster,  M.P.  for  Aberdeen  318 

Western  196 

Westminster  clock    (see    also   Clocks) 
187,  207,  213,  217,  240,  270 

Wexford  harbour  (see  Harbours) 


Wheatstone  142 

Whewell,  William  22,  25,  26,  31,  33, 
43.  47,  53,  63,  66,  68,  69,  71,  72, 
78—80,  83—85,  90,  100,  103,  105, 
117—119,  142,  148,  150,  152,  161, 
169,  173,  227,  230,  232,  238,  266 

White  House,  the,  335,  346,  347,  363, 

365 

Wigram,  pupil  64 
Williams,  John  83,  173,  174 
Williamson,  pupil  49 
Williamstown  Observatory  252 
Wilson,  Prof.  196 
Winchester  145 
Winds  (see  Meteorology) 
Winning  27,  30 
Wood,  Sir  Charles  109,  130 — 135,  222, 

227 

Wood,  Dr  47 

Woodbridge,  Suffolk  358,  362 
Woodhouse,  Prof.  29,  40,  47,  48,  72, 

77,  79 

Woolwich  Academy  (see  Examinations) 
Wordsworth,  Dr,  Master  of  Trin.  Coll. 

31'  36,  53,  6l 

Wordsworth,  poet  64,  76,  149,  150 
Wrede,  Baron  210 
Wynter,  Vice-Chancellor,  Oxford  157, 

1 66 

Yolland,  Col.  154,  202 
York  Cathedral  50,  147,  149,  176 
Young,  Dr  55,  67,  69,  74,  77,  79,  82, 

85,87 


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